All Exams >
Civil Engineering (CE) >
RRB JE Mock Test Series for Civil Engineering (CE) 2025 >
All Questions
All questions of Chemistry for Civil Engineering (CE) Exam
The element used in the manufacture of safety matches is –- a)Phosphorous
- b)Magnesium
- c)Silicon
- d)Sulphur
Correct answer is option 'A'. Can you explain this answer?
The element used in the manufacture of safety matches is –
a)
Phosphorous
b)
Magnesium
c)
Silicon
d)
Sulphur
|
Dia Mehta answered |
One end of a match is coated with a material that can be ignited by frictional heat generated by striking the match against a suitable surface. The coated end of a match, known as the match "head," contains either phosphorus or phosphorus sesquisulfide as the active ingredient and gelatin as a binder.
Diamond is harder than graphite because of –- a)difference in layers of atoms
- b)tetrahedral structure of diamond
- c)difference of crystalline structures
- d)None of these
Correct answer is option 'A'. Can you explain this answer?
Diamond is harder than graphite because of –
a)
difference in layers of atoms
b)
tetrahedral structure of diamond
c)
difference of crystalline structures
d)
None of these
|
Eshaan Kapoor answered |
Diamond is harder than graphite because diamond has a more complex structure. Diamond's structure is like many pentagons connected together, each pentagon sharing a side with another pentagon or each pentagon sharing a point with another pentagon. All the points are linked together in some way. Graphite's structure is very loose, with its bonds forming layers.
Which of the following elements replaced eka-Aluminium in Mendeleev's Periodic Table?- a)Scandium
- b)Gallium
- c)Titanium
- d)Germanium
Correct answer is option 'B'. Can you explain this answer?
Which of the following elements replaced eka-Aluminium in Mendeleev's Periodic Table?
a)
Scandium
b)
Gallium
c)
Titanium
d)
Germanium
|
Sheikha Shah answered |
Answer :
Gallium
Gallium replaced eka-Aluminium in Mendeleev's Periodic Table.
Which gas is used to manufacture vanaspati from vegetable oil is -- a)carbon dioxide
- b)nitrogen
- c)oxygen
- d)hydrogen
Correct answer is option 'D'. Can you explain this answer?
Which gas is used to manufacture vanaspati from vegetable oil is -
a)
carbon dioxide
b)
nitrogen
c)
oxygen
d)
hydrogen
|
|
Deepa dubey answered |
Gas used to manufacture vanaspati from vegetable oil: Hydrogen
Explanation:
Vanaspati is a form of hydrogenated vegetable oil that is solid at room temperature. It is commonly used as a substitute for ghee (clarified butter) in cooking. The process of manufacturing vanaspati involves the use of hydrogen gas.
Process of manufacturing vanaspati:
1. Hydrogenation: The first step in manufacturing vanaspati is the hydrogenation of vegetable oil. This process involves the addition of hydrogen gas to vegetable oil under specific conditions of temperature and pressure.
2. Catalyst: The hydrogenation process is catalyzed by the presence of a catalyst, such as nickel or palladium. The catalyst helps in the breaking of double bonds present in the unsaturated fatty acids of vegetable oil and facilitates the addition of hydrogen atoms.
3. Saturation of fatty acids: During hydrogenation, the unsaturated fatty acids present in vegetable oil are saturated with hydrogen atoms. This process converts liquid vegetable oil into a solid form, which is characteristic of vanaspati.
4. Trans fatty acids: In the process of hydrogenation, some of the unsaturated fatty acids undergo a partial rearrangement, resulting in the formation of trans fatty acids. Trans fatty acids are known to have adverse health effects and are considered unhealthy when consumed in excessive amounts.
5. Deodorization and refining: After the hydrogenation process, the vanaspati undergoes further refining steps, including deodorization to remove any undesirable odors and impurities. This refining process helps in enhancing the quality and shelf life of vanaspati.
6. Addition of flavor and color: Finally, flavoring agents and food-grade colors may be added to the refined vanaspati to enhance its taste and appearance.
Conclusion:
Hydrogen gas is used in the manufacturing process of vanaspati from vegetable oil. The hydrogenation process involves saturating the unsaturated fatty acids in vegetable oil with hydrogen atoms, resulting in the solid form of vanaspati.
Explanation:
Vanaspati is a form of hydrogenated vegetable oil that is solid at room temperature. It is commonly used as a substitute for ghee (clarified butter) in cooking. The process of manufacturing vanaspati involves the use of hydrogen gas.
Process of manufacturing vanaspati:
1. Hydrogenation: The first step in manufacturing vanaspati is the hydrogenation of vegetable oil. This process involves the addition of hydrogen gas to vegetable oil under specific conditions of temperature and pressure.
2. Catalyst: The hydrogenation process is catalyzed by the presence of a catalyst, such as nickel or palladium. The catalyst helps in the breaking of double bonds present in the unsaturated fatty acids of vegetable oil and facilitates the addition of hydrogen atoms.
3. Saturation of fatty acids: During hydrogenation, the unsaturated fatty acids present in vegetable oil are saturated with hydrogen atoms. This process converts liquid vegetable oil into a solid form, which is characteristic of vanaspati.
4. Trans fatty acids: In the process of hydrogenation, some of the unsaturated fatty acids undergo a partial rearrangement, resulting in the formation of trans fatty acids. Trans fatty acids are known to have adverse health effects and are considered unhealthy when consumed in excessive amounts.
5. Deodorization and refining: After the hydrogenation process, the vanaspati undergoes further refining steps, including deodorization to remove any undesirable odors and impurities. This refining process helps in enhancing the quality and shelf life of vanaspati.
6. Addition of flavor and color: Finally, flavoring agents and food-grade colors may be added to the refined vanaspati to enhance its taste and appearance.
Conclusion:
Hydrogen gas is used in the manufacturing process of vanaspati from vegetable oil. The hydrogenation process involves saturating the unsaturated fatty acids in vegetable oil with hydrogen atoms, resulting in the solid form of vanaspati.
Which one amongst the following is not a Green House gas?- a)Nitrogen
- b)Carbon dioxide
- c)Carbon Monoxide
- d)Chloro fluoro carbons
Correct answer is option 'A'. Can you explain this answer?
Which one amongst the following is not a Green House gas?
a)
Nitrogen
b)
Carbon dioxide
c)
Carbon Monoxide
d)
Chloro fluoro carbons
|
|
Dia Mehta answered |
A greenhouse has (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.
Urea is a -- a)Sodium fertilizer
- b)Phosphatic fertilizer
- c)Nitrogenous fertilizer
- d)Potassium fertilizer
Correct answer is option 'C'. Can you explain this answer?
Urea is a -
a)
Sodium fertilizer
b)
Phosphatic fertilizer
c)
Nitrogenous fertilizer
d)
Potassium fertilizer
|
Faizan Khan answered |
More than 90% of world production of urea is destined for use as a nitrogen-release fertilizer. Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use.
Quartz is a crystalline form of -- a)Alumina
- b)Glass
- c)Silica
- d)Limestone
Correct answer is option 'C'. Can you explain this answer?
Quartz is a crystalline form of -
a)
Alumina
b)
Glass
c)
Silica
d)
Limestone
|
|
Dia Mehta answered |
Quartz is made up of a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. Tridymite and cristobalite are hightemperature polymorphs of SiO2 that occur in high-silica volcanic rocks. Coesite is a denser polymorph of quartz found in some meteorite impact sites and in metamorphic rocks.
In vulcanisation process, rubber can be hardened by adding -- a)Nitrogen
- b)Silicon
- c)Sulphur
- d)Alcohol
Correct answer is option 'C'. Can you explain this answer?
In vulcanisation process, rubber can be hardened by adding -
a)
Nitrogen
b)
Silicon
c)
Sulphur
d)
Alcohol
|
|
Eshaan Kapoor answered |
In order to give more strength and more elasticity, natural rubber is heated with sulphur or sulphur compounds at 150°C temperature. Vulcanized rubber has good tensile strength.
Manganite is an ore/mineral of ______.- a)Beryllium
- b)Chromium
- c)Manganese
- d)Copper
Correct answer is option 'C'. Can you explain this answer?
Manganite is an ore/mineral of ______.
a)
Beryllium
b)
Chromium
c)
Manganese
d)
Copper
|
Aryan Khanna answered |
Manganite is an ore mineral of manganese. As a manganese ore, it ranks after pyrolusite and romanechite.
The presence of which of the following salts in water causes corrosion in steamboilers?- a)Sodium Chloride
- b)Magnesium Chloride
- c)Calcium bicarbonate
- d)Potassium bicarbonate
Correct answer is option 'B'. Can you explain this answer?
The presence of which of the following salts in water causes corrosion in steamboilers?
a)
Sodium Chloride
b)
Magnesium Chloride
c)
Calcium bicarbonate
d)
Potassium bicarbonate
|
Sandeep Chavan answered |
Understanding Corrosion in Steamboilers
Corrosion in steamboilers is a significant issue that can lead to operational failures, increased maintenance costs, and safety hazards. Among various salts, Magnesium Chloride is particularly corrosive.
Why Magnesium Chloride Causes Corrosion
- Chemical Properties: Magnesium Chloride (MgCl2) is highly soluble in water and dissociates into magnesium and chloride ions. The chloride ions are notorious for their aggressive nature in promoting corrosion.
- Electrochemical Reactions: When present in water, Magnesium Chloride can initiate electrochemical reactions on the metal surfaces of the boiler. These reactions accelerate the deterioration of metal, leading to pitting and general corrosion.
- Formation of Corrosive Compounds: The presence of magnesium ions can lead to the formation of corrosive compounds, which further exacerbate metal degradation. These compounds can create localized acidic environments that are detrimental to the integrity of the boiler materials.
Comparison with Other Salts
- Sodium Chloride: While it is also corrosive, Magnesium Chloride is more aggressive under certain operating conditions typically found in steamboilers.
- Calcium Bicarbonate & Potassium Bicarbonate: These salts are generally less corrosive compared to Magnesium Chloride. They can lead to scaling rather than direct corrosion, making them less harmful to the boiler's metal surfaces.
Conclusion
In summary, the presence of Magnesium Chloride in water is particularly harmful to steamboilers due to its chemical properties and the corrosive electrochemical reactions it can initiate. This understanding is crucial for maintaining boiler efficiency and longevity.
Corrosion in steamboilers is a significant issue that can lead to operational failures, increased maintenance costs, and safety hazards. Among various salts, Magnesium Chloride is particularly corrosive.
Why Magnesium Chloride Causes Corrosion
- Chemical Properties: Magnesium Chloride (MgCl2) is highly soluble in water and dissociates into magnesium and chloride ions. The chloride ions are notorious for their aggressive nature in promoting corrosion.
- Electrochemical Reactions: When present in water, Magnesium Chloride can initiate electrochemical reactions on the metal surfaces of the boiler. These reactions accelerate the deterioration of metal, leading to pitting and general corrosion.
- Formation of Corrosive Compounds: The presence of magnesium ions can lead to the formation of corrosive compounds, which further exacerbate metal degradation. These compounds can create localized acidic environments that are detrimental to the integrity of the boiler materials.
Comparison with Other Salts
- Sodium Chloride: While it is also corrosive, Magnesium Chloride is more aggressive under certain operating conditions typically found in steamboilers.
- Calcium Bicarbonate & Potassium Bicarbonate: These salts are generally less corrosive compared to Magnesium Chloride. They can lead to scaling rather than direct corrosion, making them less harmful to the boiler's metal surfaces.
Conclusion
In summary, the presence of Magnesium Chloride in water is particularly harmful to steamboilers due to its chemical properties and the corrosive electrochemical reactions it can initiate. This understanding is crucial for maintaining boiler efficiency and longevity.
______ is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals and fungi.- a)Cellulose
- b)Glycogen
- c)Pectin
- d)Chitin
Correct answer is option 'B'. Can you explain this answer?
______ is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals and fungi.
a)
Cellulose
b)
Glycogen
c)
Pectin
d)
Chitin
|
|
Aryan Khanna answered |
Glycogen is a multi branched polysaccharide of glucose that serves as a form of emery storage in humans animals, and fungi.
A body moving in a circular path with a constant speed has a -- a)constant velocity
- b)constant acceleration
- c)constant kinetic energy
- d)constant displacement
Correct answer is option 'C'. Can you explain this answer?
A body moving in a circular path with a constant speed has a -
a)
constant velocity
b)
constant acceleration
c)
constant kinetic energy
d)
constant displacement
|
|
Shradha nayar answered |
Understanding Circular Motion
When a body moves in a circular path at a constant speed, it exhibits unique characteristics due to its continuous change in direction. Let's explore why the correct answer is constant kinetic energy.
Constant Speed vs. Velocity
- Speed vs. Velocity: Speed is a scalar quantity, meaning it only has magnitude. In contrast, velocity is a vector quantity, which has both magnitude and direction.
- Changing Direction: Although the speed is constant, the direction of the velocity vector changes continuously, making the velocity itself non-constant.
Acceleration in Circular Motion
- Centripetal Acceleration: A body moving in a circular path experiences centripetal acceleration directed towards the center of the circle.
- Constant Acceleration: While this acceleration is constant in magnitude, its direction changes, indicating that it is not constant in the conventional sense.
Constant Kinetic Energy
- Kinetic Energy Formula: Kinetic energy (KE) is given by the formula KE = 1/2 mv², where m is mass and v is speed.
- Impact of Constant Speed: Since the speed remains unchanged during circular motion, the kinetic energy of the body also remains constant.
- Independence from Direction: Kinetic energy does not depend on the direction of motion, only on the speed.
Displacement in Circular Motion
- Variable Displacement: While moving in a circular path, the displacement (the shortest distance between the initial and final points) changes continuously.
- Cyclic Nature: After one complete revolution, the displacement is zero, further indicating that it is not constant.
In summary, while the body moving in a circular path has constant speed and kinetic energy, its velocity, acceleration, and displacement vary. Thus, the correct answer is option 'C' - constant kinetic energy.
When a body moves in a circular path at a constant speed, it exhibits unique characteristics due to its continuous change in direction. Let's explore why the correct answer is constant kinetic energy.
Constant Speed vs. Velocity
- Speed vs. Velocity: Speed is a scalar quantity, meaning it only has magnitude. In contrast, velocity is a vector quantity, which has both magnitude and direction.
- Changing Direction: Although the speed is constant, the direction of the velocity vector changes continuously, making the velocity itself non-constant.
Acceleration in Circular Motion
- Centripetal Acceleration: A body moving in a circular path experiences centripetal acceleration directed towards the center of the circle.
- Constant Acceleration: While this acceleration is constant in magnitude, its direction changes, indicating that it is not constant in the conventional sense.
Constant Kinetic Energy
- Kinetic Energy Formula: Kinetic energy (KE) is given by the formula KE = 1/2 mv², where m is mass and v is speed.
- Impact of Constant Speed: Since the speed remains unchanged during circular motion, the kinetic energy of the body also remains constant.
- Independence from Direction: Kinetic energy does not depend on the direction of motion, only on the speed.
Displacement in Circular Motion
- Variable Displacement: While moving in a circular path, the displacement (the shortest distance between the initial and final points) changes continuously.
- Cyclic Nature: After one complete revolution, the displacement is zero, further indicating that it is not constant.
In summary, while the body moving in a circular path has constant speed and kinetic energy, its velocity, acceleration, and displacement vary. Thus, the correct answer is option 'C' - constant kinetic energy.
The fuel that is used in modern submarines is –- a)Nuclear fuel
- b)Petrol
- c)Coal
- d)Diesel
Correct answer is option 'A'. Can you explain this answer?
The fuel that is used in modern submarines is –
a)
Nuclear fuel
b)
Petrol
c)
Coal
d)
Diesel
|
|
Dia Mehta answered |
Nuclear power is now used in all large submarines, but due to the high cost and large size of nuclear reactors, smaller submarines still use diesel-electric propulsion. The ratio of larger to smaller submarines depends on strategic needs. The US Navy, drench Navy, and the British Royal Navy operate only nuclear submarines.
Which one among the following polymers is used for making bullet-proof material?- a)Polyvinyl chloride
- b)Polystyrene
- c)Polyethylene
- d)Polyamide
Correct answer is option 'C'. Can you explain this answer?
Which one among the following polymers is used for making bullet-proof material?
a)
Polyvinyl chloride
b)
Polystyrene
c)
Polyethylene
d)
Polyamide
|
|
Eshaan Kapoor answered |
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
Which is the purest form of iron?- a)Steel
- b)Cast iron
- c)Pig iron
- d)Wrought iron
Correct answer is option 'D'. Can you explain this answer?
Which is the purest form of iron?
a)
Steel
b)
Cast iron
c)
Pig iron
d)
Wrought iron
|
Aruna singh answered |
Wrought iron is the purest form of iron among the given options.
Explanation:
Wrought iron is a form of iron that is almost entirely free from impurities and contains a very low percentage of carbon (less than 0.1%). It is characterized by its fibrous structure and is known for its high ductility and malleability.
Here are some key points that explain why wrought iron is considered the purest form of iron:
1. Carbon content:
- Wrought iron has the lowest carbon content among the given options. It contains less than 0.1% carbon, making it nearly pure iron.
- In comparison, steel contains a higher carbon content (up to 2%) which gives it greater strength but reduces its purity.
- Cast iron contains a higher carbon content (2-4%) and is known for its brittleness and inability to be forged.
- Pig iron is the crudest form of iron and has a high carbon content (3-4%). It is also brittle and cannot be used directly.
2. Impurities:
- Wrought iron is produced by a refining process known as puddling, which removes impurities such as sulfur and phosphorus.
- This process involves melting pig iron in a reverberatory furnace and stirring it to oxidize the impurities, which are then absorbed by the slag.
- The repeated stirring and oxidation help to purify the iron, resulting in wrought iron with minimal impurities.
3. Physical properties:
- Wrought iron is known for its fibrous structure, which is a result of the slag being worked into the iron during the refining process.
- This fibrous structure gives wrought iron its characteristic grainy appearance and enhances its mechanical properties, such as ductility and malleability.
- It can be easily forged, welded, and shaped into various forms without losing its strength.
In conclusion, wrought iron is considered the purest form of iron due to its low carbon content and the removal of impurities during the refining process. Its high ductility, malleability, and nearly pure iron composition make it suitable for various applications, including decorative ironwork, fencing, and historical artifacts.
Explanation:
Wrought iron is a form of iron that is almost entirely free from impurities and contains a very low percentage of carbon (less than 0.1%). It is characterized by its fibrous structure and is known for its high ductility and malleability.
Here are some key points that explain why wrought iron is considered the purest form of iron:
1. Carbon content:
- Wrought iron has the lowest carbon content among the given options. It contains less than 0.1% carbon, making it nearly pure iron.
- In comparison, steel contains a higher carbon content (up to 2%) which gives it greater strength but reduces its purity.
- Cast iron contains a higher carbon content (2-4%) and is known for its brittleness and inability to be forged.
- Pig iron is the crudest form of iron and has a high carbon content (3-4%). It is also brittle and cannot be used directly.
2. Impurities:
- Wrought iron is produced by a refining process known as puddling, which removes impurities such as sulfur and phosphorus.
- This process involves melting pig iron in a reverberatory furnace and stirring it to oxidize the impurities, which are then absorbed by the slag.
- The repeated stirring and oxidation help to purify the iron, resulting in wrought iron with minimal impurities.
3. Physical properties:
- Wrought iron is known for its fibrous structure, which is a result of the slag being worked into the iron during the refining process.
- This fibrous structure gives wrought iron its characteristic grainy appearance and enhances its mechanical properties, such as ductility and malleability.
- It can be easily forged, welded, and shaped into various forms without losing its strength.
In conclusion, wrought iron is considered the purest form of iron due to its low carbon content and the removal of impurities during the refining process. Its high ductility, malleability, and nearly pure iron composition make it suitable for various applications, including decorative ironwork, fencing, and historical artifacts.
What is "milk of magnesia" chemically?- a)Magnesium carbonate
- b)Sodium bicarbonate
- c)Calcium hydroxide
- d)Magnesium hydroxide
Correct answer is option 'D'. Can you explain this answer?
What is "milk of magnesia" chemically?
a)
Magnesium carbonate
b)
Sodium bicarbonate
c)
Calcium hydroxide
d)
Magnesium hydroxide
|
|
Anaya Patel answered |
Magnesium hydroxide is an inorganic compound with the chemical formula Mg(OH)2. As a suspension in water, it is often called milk of magnesia because of its milk-like appearance. The solid mineral form of magnesium hydroxide is known as brucite.
The major harmful gas emitted by automobile vehicles which causes air pollution is –- a)Carbon Monoxide
- b)Methane
- c)Carbon dioxide
- d)Ozone gas
Correct answer is option 'A'. Can you explain this answer?
The major harmful gas emitted by automobile vehicles which causes air pollution is –
a)
Carbon Monoxide
b)
Methane
c)
Carbon dioxide
d)
Ozone gas
|
|
Eshaan Kapoor answered |
Carbon monoxide is the major harmful gas emitted by the automobile vehicles which causes air pollution. Carbon monoxide (CO) - A product of incomplete combustion, carbon monoxide reduces the blood's ability to carry oxygen: overexposure (carbon monoxide poisoning) may be fatal. Carbon Monoxide poisoning is a major killer.
The gas usually causing explosions in coal mines is –- a)Hydrogen
- b)Carbon monoxide
- c)Air
- d)Methane
Correct answer is option 'D'. Can you explain this answer?
The gas usually causing explosions in coal mines is –
a)
Hydrogen
b)
Carbon monoxide
c)
Air
d)
Methane
|
|
Dia Mehta answered |
Firedamp is flammable gas found in coal mines. It is the name given to a number of flammable gases, especially methane.
Who discovered the atom bomb?- a)Madam Curie
- b)Pierre Curie
- c)Otto Hahn
- d)Albert Einstein
Correct answer is option 'C'. Can you explain this answer?
Who discovered the atom bomb?
a)
Madam Curie
b)
Pierre Curie
c)
Otto Hahn
d)
Albert Einstein
|
|
Aryan Khanna answered |
Otto Hahn, (8 March, 1879 - 28 July, 1968) was a German chemist and Nobel laureate, a pioneer in the fields of radioactivity and radiochemistry. He is regarded as "the father of nuclear chemistry". On 15 November 1945 the Royal Swedish Academy of Sciences announced that Hahn had been awarded the 1944 Nobel Prize in Chemistry "for his discovery of the fission of heavy atomic nuclei." Otto Hahn received many governmental honours and academic awards from all over the world for his scientific work.
Potassium Permanganate is used for purifying drinking water, because -- a)It dissolves the impurities of water
- b)It is a sterilizing agent
- c)It is an oxidising agent
- d)It is a reducing agent
Correct answer is option 'C'. Can you explain this answer?
Potassium Permanganate is used for purifying drinking water, because -
a)
It dissolves the impurities of water
b)
It is a sterilizing agent
c)
It is an oxidising agent
d)
It is a reducing agent
|
|
Aryan Khanna answered |
Potassium permanganate is a point-of entry treatment method that oxidizes dissolved iron, manganese, and hydrogen sulfide into solid particles that are filtered out of the water.
What is the most commonly used substance in fluorescent tubes?- a)Sodium oxide and argon
- b)Sodium vapour and neon
- c)Mercury vapour and argon
- d)Mercury oxide and neon
Correct answer is option 'C'. Can you explain this answer?
What is the most commonly used substance in fluorescent tubes?
a)
Sodium oxide and argon
b)
Sodium vapour and neon
c)
Mercury vapour and argon
d)
Mercury oxide and neon
|
|
Eshaan Kapoor answered |
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapour. it contains mercury vapour and argon. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful light more efficiently than an incandescent lamp.
The Refrigerant 'FREON' is –- a)Calcium Tetra Fluoride
- b)Difluoro Dichloro Methane
- c)Fluorspar and Felspar
- d)Hydrofluosilicic Acid
Correct answer is option 'B'. Can you explain this answer?
The Refrigerant 'FREON' is –
a)
Calcium Tetra Fluoride
b)
Difluoro Dichloro Methane
c)
Fluorspar and Felspar
d)
Hydrofluosilicic Acid
|
|
Eshaan Kapoor answered |
Dichlorodifluorornethane (R-12), is a colourless gas, and usually sold under the brand name Freon-12, is a chlorofluorocarbon halornethane (CFC), used as a refrigrant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in the United States along with many other countries in 1994 clue to concerns about damage to the ozone layer. It is soluble in many organic solvents.
Which one of the following is a major green gas?- a)Carbon dioxide
- b)Chloro fluorocarbon
- c)Carbon monoxide
- d)Freon
Correct answer is option 'A'. Can you explain this answer?
Which one of the following is a major green gas?
a)
Carbon dioxide
b)
Chloro fluorocarbon
c)
Carbon monoxide
d)
Freon
|
|
Ramya jain answered |
Carbon Dioxide as a Major Green Gas
Carbon dioxide (CO2) is a major greenhouse gas that contributes significantly to global warming and climate change. Here's why it is considered a major green gas:
- Abundance: Carbon dioxide is one of the most abundant greenhouse gases in the Earth's atmosphere, primarily due to human activities such as burning fossil fuels, deforestation, and industrial processes.
- Global Warming Potential: CO2 has a high global warming potential, meaning it has a strong ability to trap heat in the atmosphere and contribute to the greenhouse effect.
- Longevity: Carbon dioxide remains in the atmosphere for a long time, with some of it staying for thousands of years. This long-lasting nature makes it a persistent greenhouse gas.
- Impact on Climate: The excessive accumulation of carbon dioxide in the atmosphere is causing temperatures to rise, ice caps to melt, sea levels to rise, and extreme weather events to become more frequent and severe.
- Regulation: Due to its significant role in climate change, efforts are being made globally to reduce CO2 emissions through policies, agreements, and initiatives aimed at mitigating its impact on the environment.
In conclusion, carbon dioxide is a major greenhouse gas with far-reaching implications for the planet's climate and ecosystems. Addressing the issue of CO2 emissions is crucial in combating global warming and its associated consequences.
Carbon dioxide (CO2) is a major greenhouse gas that contributes significantly to global warming and climate change. Here's why it is considered a major green gas:
- Abundance: Carbon dioxide is one of the most abundant greenhouse gases in the Earth's atmosphere, primarily due to human activities such as burning fossil fuels, deforestation, and industrial processes.
- Global Warming Potential: CO2 has a high global warming potential, meaning it has a strong ability to trap heat in the atmosphere and contribute to the greenhouse effect.
- Longevity: Carbon dioxide remains in the atmosphere for a long time, with some of it staying for thousands of years. This long-lasting nature makes it a persistent greenhouse gas.
- Impact on Climate: The excessive accumulation of carbon dioxide in the atmosphere is causing temperatures to rise, ice caps to melt, sea levels to rise, and extreme weather events to become more frequent and severe.
- Regulation: Due to its significant role in climate change, efforts are being made globally to reduce CO2 emissions through policies, agreements, and initiatives aimed at mitigating its impact on the environment.
In conclusion, carbon dioxide is a major greenhouse gas with far-reaching implications for the planet's climate and ecosystems. Addressing the issue of CO2 emissions is crucial in combating global warming and its associated consequences.
The pH of a neutral solution is -- a)0-7
- b)7
- c)7-14
- d)None of the above
Correct answer is option 'B'. Can you explain this answer?
The pH of a neutral solution is -
a)
0-7
b)
7
c)
7-14
d)
None of the above
|
|
Dia Mehta answered |
The pH of a neutral solution is 7. Values less than 7 on the pH scale represent an acidic solution. As the pH value increases from 7 to 14, the solution turns more basic.
Commercial Vaseline is derived from -- a)plant gums
- b)coal tar
- c)wool wax
- d)petroleum
Correct answer is option 'D'. Can you explain this answer?
Commercial Vaseline is derived from -
a)
plant gums
b)
coal tar
c)
wool wax
d)
petroleum
|
|
Faizan Khan answered |
Vaseline is a brand of petroleum jelly based products owned by Anglo-Dutch company Unilever. While Vaseline can be used as a lubricant, it is also a useful moisture insulator for local skin conditions characterized by tissue dehydration. Vaseline helps protect minor cuts and burns.
Which of the following is a physical change?- a)oxidation
- b)reduction
- c)sublimation
- d)decomposition
Correct answer is option 'C'. Can you explain this answer?
Which of the following is a physical change?
a)
oxidation
b)
reduction
c)
sublimation
d)
decomposition
|
|
Faizan Khan answered |
Sublimation is a type of phase transition, or a change in a state of matter, just like melting, freezing, and evaporation.
Which of the following is a super-cooled liquid?- a)Ice-cream
- b)Ammonia
- c)Glass
- d)Wood
Correct answer is option 'C'. Can you explain this answer?
Which of the following is a super-cooled liquid?
a)
Ice-cream
b)
Ammonia
c)
Glass
d)
Wood
|
|
Faizan Khan answered |
Glass is considered to be a super - cooled liquid due to its lack of a first-order phase transition where certain thermodynamic variables such as volume, entropy and enthalpy are discontinuous through the glass transition. range. However, the glass transition may be described as analogous to a second-order phase transition where the intensive thermodynamic variables such as the thermal expansivity and heat capacity are discontinuous.
Soap is prepared by boiling caustic soda with –- a)Alcohol
- b)Kerosene oil
- c)Glycerine
- d)Fats
Correct answer is option 'D'. Can you explain this answer?
Soap is prepared by boiling caustic soda with –
a)
Alcohol
b)
Kerosene oil
c)
Glycerine
d)
Fats
|
|
Eshaan Kapoor answered |
The most basic kind of soap is made from cuastic soda and animal fat. The two are heated together, and then cooled. The process is called "saponification". In technical terms, saponification involves base (usually caustic soda NaOH) hydrolysis of triglyeerides which are esters of fatty acids, to form the sodium salt, of a carboxylate.
Pasteurisation is the process in which milk is heated to –- a)60°C for 10 minutes
- b)63° C for 20 minutes
- c)63°C for 30 minutes
- d)72°C for 10 minutes
Correct answer is option 'C'. Can you explain this answer?
Pasteurisation is the process in which milk is heated to –
a)
60°C for 10 minutes
b)
63° C for 20 minutes
c)
63°C for 30 minutes
d)
72°C for 10 minutes
|
|
Faizan Khan answered |
Pasteurization for pasteurisation) is a process of heating a food, which is usually a liquid, to a specific temperature for a predefined length of time and then immediately cooling it after it is removed from the heat. This process slows spoilage due to microbial growth in the food. Unlike sterilization, pasteurization is not intended to kill all micro organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease (assuming the pasteurized product is stored as indicated and is consumed before its expiration date).
The gas used for filling weather balloons is –- a)helium
- b)hydrogen
- c)air
- d)nitrogen
Correct answer is option 'A'. Can you explain this answer?
The gas used for filling weather balloons is –
a)
helium
b)
hydrogen
c)
air
d)
nitrogen
|
|
Eshaan Kapoor answered |
A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig bladder. Some balloons are used for decorative purposes, while others are used for practical purposes such as meteorology, medical treatment, military defense, or transportation.
German silver, an alloy, does not contain the metal –- a)Nickel
- b)Zinc
- c)Copper
- d)Silver
Correct answer is option 'D'. Can you explain this answer?
German silver, an alloy, does not contain the metal –
a)
Nickel
b)
Zinc
c)
Copper
d)
Silver
|
|
Dia Mehta answered |
Nickel silver is a copper alloy with nickel and oft6n. zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers in imitation of the Chinese alloy known as paktong (Cupronickel) All modern, commercially important nickel silvers (such as those standardized under ASTM B 122) contain significant amounts of zinc, and are sometimes considered a subset of brass.
Percentage of carbon in steel ranges from –- a)0.1 to 1.5
- b)1.5 to 3.0
- c)3.0 to 4.0
- d)4.0 to 6.0
Correct answer is option 'A'. Can you explain this answer?
Percentage of carbon in steel ranges from –
a)
0.1 to 1.5
b)
1.5 to 3.0
c)
3.0 to 4.0
d)
4.0 to 6.0
|
|
Naman dey answered |
Percentage of Carbon in Steel
Steel is an alloy of iron and carbon, where the percentage of carbon in steel determines its properties and characteristics. The percentage of carbon in steel typically ranges from 0.1% to 1.5%, with different levels of carbon corresponding to different types of steel.
Explanation:
- Low Carbon Steel: Steel with a carbon content ranging from 0.1% to 0.3% is classified as low carbon steel. This type of steel is easy to form and shape, making it suitable for applications such as automotive body panels and wire.
- Medium Carbon Steel: Steel with a carbon content between 0.3% and 0.6% falls into the category of medium carbon steel. This type of steel offers a balance of strength and ductility and is commonly used in construction and machinery.
- High Carbon Steel: Steel with a carbon content ranging from 0.6% to 1.5% is classified as high carbon steel. This type of steel is known for its hardness and wear resistance, making it suitable for applications such as cutting tools and springs.
By controlling the percentage of carbon in steel, manufacturers can tailor the properties of the steel to meet specific requirements for different applications. The range of 0.1% to 1.5% covers the most common types of carbon steel used in various industries.
Steel is an alloy of iron and carbon, where the percentage of carbon in steel determines its properties and characteristics. The percentage of carbon in steel typically ranges from 0.1% to 1.5%, with different levels of carbon corresponding to different types of steel.
Explanation:
- Low Carbon Steel: Steel with a carbon content ranging from 0.1% to 0.3% is classified as low carbon steel. This type of steel is easy to form and shape, making it suitable for applications such as automotive body panels and wire.
- Medium Carbon Steel: Steel with a carbon content between 0.3% and 0.6% falls into the category of medium carbon steel. This type of steel offers a balance of strength and ductility and is commonly used in construction and machinery.
- High Carbon Steel: Steel with a carbon content ranging from 0.6% to 1.5% is classified as high carbon steel. This type of steel is known for its hardness and wear resistance, making it suitable for applications such as cutting tools and springs.
By controlling the percentage of carbon in steel, manufacturers can tailor the properties of the steel to meet specific requirements for different applications. The range of 0.1% to 1.5% covers the most common types of carbon steel used in various industries.
The ratio of pure gold in 18 carat gold is- a)60%
- b)75%
- c)80%
- d)90%
Correct answer is option 'B'. Can you explain this answer?
The ratio of pure gold in 18 carat gold is
a)
60%
b)
75%
c)
80%
d)
90%
|
|
Dia Mehta answered |
There are various grades of gold purity, determined by the ratio of their alloy composition and rated by a karat system. Typical karat purities range from 10 karats to 24 karats (pure gold), with a wide variation of usage from country to country, 18 karat gold consists of 75% gold and 25% alloy metals. 18 karat gold has been found to be the perfect balance between gold purity and strength. Brilliance offers a variety of exquisite 18 karat gold jewelry.
The freezing point of fresh water is -- a)0°C
- b)4°C
- c)3°C
- d)5°C
Correct answer is option 'A'. Can you explain this answer?
The freezing point of fresh water is -
a)
0°C
b)
4°C
c)
3°C
d)
5°C
|
|
Dia Mehta answered |
Ocean water freezes just like freshwater, but at lower temperatures. Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit, because of the salt in it.
The gas used for artificial fruit ripening of green fruit is –- a)Ethylene
- b)Acetylene
- c)Ethane
- d)Methane
Correct answer is option 'A'. Can you explain this answer?
The gas used for artificial fruit ripening of green fruit is –
a)
Ethylene
b)
Acetylene
c)
Ethane
d)
Methane
|
Geeta jain answered |
Understanding Artificial Fruit Ripening
Artificial fruit ripening is a common practice in agriculture, particularly for fruits that are harvested while still green. This process aims to enhance the color, flavor, and texture of the fruit, making it more appealing for consumers.
Role of Ethylene in Ripening
- Ethylene is a naturally occurring plant hormone, crucial for the ripening of fruits.
- It promotes various physiological processes, including color change, softening, and the development of flavor and aroma.
Why Ethylene is Used
- Natural Process: Ethylene is produced by many fruits during their natural ripening. By applying ethylene gas, the ripening process is mimicked and accelerated.
- Efficiency: Ethylene is effective even in small concentrations, making it an economical choice for commercial ripening.
- Controlled Environment: Ethylene can be applied in controlled environments to ensure uniform ripening, reducing spoilage and waste.
Comparison with Other Gases
- Acetylene: Often confused with ethylene, acetylene can stimulate ripening but is less effective and can be harmful in higher concentrations.
- Ethane and Methane: These gases do not have significant roles in the ripening process and are not used for this purpose.
Conclusion
The use of ethylene for artificial ripening has revolutionized the way fruits are marketed and consumed. Its effectiveness, combined with its natural role in fruit development, makes it the preferred choice for ripening green fruits efficiently.
Artificial fruit ripening is a common practice in agriculture, particularly for fruits that are harvested while still green. This process aims to enhance the color, flavor, and texture of the fruit, making it more appealing for consumers.
Role of Ethylene in Ripening
- Ethylene is a naturally occurring plant hormone, crucial for the ripening of fruits.
- It promotes various physiological processes, including color change, softening, and the development of flavor and aroma.
Why Ethylene is Used
- Natural Process: Ethylene is produced by many fruits during their natural ripening. By applying ethylene gas, the ripening process is mimicked and accelerated.
- Efficiency: Ethylene is effective even in small concentrations, making it an economical choice for commercial ripening.
- Controlled Environment: Ethylene can be applied in controlled environments to ensure uniform ripening, reducing spoilage and waste.
Comparison with Other Gases
- Acetylene: Often confused with ethylene, acetylene can stimulate ripening but is less effective and can be harmful in higher concentrations.
- Ethane and Methane: These gases do not have significant roles in the ripening process and are not used for this purpose.
Conclusion
The use of ethylene for artificial ripening has revolutionized the way fruits are marketed and consumed. Its effectiveness, combined with its natural role in fruit development, makes it the preferred choice for ripening green fruits efficiently.
Colour imparted to the Bunsen flame by strontium salt is -- a)bluish green
- b)apple-green
- c)brick red
- d)crimson red
Correct answer is option 'D'. Can you explain this answer?
Colour imparted to the Bunsen flame by strontium salt is -
a)
bluish green
b)
apple-green
c)
brick red
d)
crimson red
|
|
Trisha nayar answered |
Strontium and Flame Colors
The color imparted to a Bunsen flame by strontium salts is primarily due to the electronic transitions of the strontium ions when they are heated.
Understanding Flame Tests
- Flame tests are qualitative analysis techniques used to identify the presence of certain metal ions based on the characteristic colors they emit when heated.
- When strontium salts, such as strontium chloride (SrCl2) or strontium nitrate (Sr(NO3)2), are introduced into a Bunsen flame, the heat excites the electrons in the strontium ions.
Color Emission
- As the excited electrons return to their ground state, they release energy in the form of light.
- Strontium specifically emits light in the red region of the spectrum, producing a distinct and recognizable color.
Characteristics of the Flame Color
- The flame produced is often described as "crimson red" or "brick red," which is a deep red hue that easily distinguishes it from other metal ions.
- This property is useful in various applications, including pyrotechnics and analytical chemistry, where identifying the presence of strontium is crucial.
Conclusion
- Thus, the correct answer to the question regarding the color imparted to the Bunsen flame by strontium salt is option 'D' - "crimson red." This vivid color is a result of the unique interaction between strontium ions and heat, making strontium a notable element in flame tests.
The color imparted to a Bunsen flame by strontium salts is primarily due to the electronic transitions of the strontium ions when they are heated.
Understanding Flame Tests
- Flame tests are qualitative analysis techniques used to identify the presence of certain metal ions based on the characteristic colors they emit when heated.
- When strontium salts, such as strontium chloride (SrCl2) or strontium nitrate (Sr(NO3)2), are introduced into a Bunsen flame, the heat excites the electrons in the strontium ions.
Color Emission
- As the excited electrons return to their ground state, they release energy in the form of light.
- Strontium specifically emits light in the red region of the spectrum, producing a distinct and recognizable color.
Characteristics of the Flame Color
- The flame produced is often described as "crimson red" or "brick red," which is a deep red hue that easily distinguishes it from other metal ions.
- This property is useful in various applications, including pyrotechnics and analytical chemistry, where identifying the presence of strontium is crucial.
Conclusion
- Thus, the correct answer to the question regarding the color imparted to the Bunsen flame by strontium salt is option 'D' - "crimson red." This vivid color is a result of the unique interaction between strontium ions and heat, making strontium a notable element in flame tests.
Detergents are –- a)Sodium salts of fatty acids
- b)Sodium salts of sulphonic acids
- c)Sodium salt of benzoic acid
- d)None of the above
Correct answer is option 'B'. Can you explain this answer?
Detergents are –
a)
Sodium salts of fatty acids
b)
Sodium salts of sulphonic acids
c)
Sodium salt of benzoic acid
d)
None of the above
|
|
Shivani das answered |
Understanding Detergents
Detergents are substances used for cleaning and they play a vital role in various cleaning applications. They can be categorized based on their chemical structure and the type of surfactants they contain.
Types of Detergents
- Sodium Salts of Fatty Acids: These are traditional soaps made from natural fats and oils. They work effectively in soft water but may not perform well in hard water. Thus, they are not classified as synthetic detergents.
- Sodium Salts of Sulphonic Acids: This is the correct answer. Synthetic detergents, commonly used in household and industrial cleaning products, are derived from petrochemicals and often take the form of sodium salts of sulfonic acids. These detergents are effective in hard water, provide better cleaning power, and are designed to work in a variety of conditions.
- Sodium Salt of Benzoic Acid: While this compound can serve as a preservative in food, it is not classified as a detergent. It does not possess the surfactant properties necessary for cleaning applications.
Conclusion
The correct classification of detergents is essential to understand their functionality and application. Sodium salts of sulfonic acids are designed to provide enhanced cleaning capabilities, making option 'B' the correct choice. Their effectiveness in hard water and ability to emulsify oils and dirt are what set them apart from traditional soap-based cleaners.
Detergents are substances used for cleaning and they play a vital role in various cleaning applications. They can be categorized based on their chemical structure and the type of surfactants they contain.
Types of Detergents
- Sodium Salts of Fatty Acids: These are traditional soaps made from natural fats and oils. They work effectively in soft water but may not perform well in hard water. Thus, they are not classified as synthetic detergents.
- Sodium Salts of Sulphonic Acids: This is the correct answer. Synthetic detergents, commonly used in household and industrial cleaning products, are derived from petrochemicals and often take the form of sodium salts of sulfonic acids. These detergents are effective in hard water, provide better cleaning power, and are designed to work in a variety of conditions.
- Sodium Salt of Benzoic Acid: While this compound can serve as a preservative in food, it is not classified as a detergent. It does not possess the surfactant properties necessary for cleaning applications.
Conclusion
The correct classification of detergents is essential to understand their functionality and application. Sodium salts of sulfonic acids are designed to provide enhanced cleaning capabilities, making option 'B' the correct choice. Their effectiveness in hard water and ability to emulsify oils and dirt are what set them apart from traditional soap-based cleaners.
The chief constituent of vinegar is –- a)Formic acid
- b)Acetic acid
- c)Salycylic acid
- d)Oxalic acid
Correct answer is option 'B'. Can you explain this answer?
The chief constituent of vinegar is –
a)
Formic acid
b)
Acetic acid
c)
Salycylic acid
d)
Oxalic acid
|
|
Aryan Khanna answered |
Vinegar is a liquid substance consisting mainly of acetic acid (CH3CO2H) and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. It is today mainly used in the kitchen as a general cooking ingredient, but historically, as the most easily available mild acid, it had a great variety of industrial, medical, and domestic uses.
The acid used in lead storage cells is –- a)phosphoric acid
- b)hydrochloric acid
- c)nitric acid
- d)sulphuric acid
Correct answer is option 'D'. Can you explain this answer?
The acid used in lead storage cells is –
a)
phosphoric acid
b)
hydrochloric acid
c)
nitric acid
d)
sulphuric acid
|
|
Aryan Khanna answered |
Dilute sulfuric acid (H2SO4) serves as the electrolyte in a lead storage battery. The electrodes of the cells in a lead storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The opehings of the cathodic grid is filled with lead dioxide (PBO2).
Which of the following gases makes bread or cake rise making them soft and spongy?- a)CO
- b)H2
- c)CO2
- d)O2
Correct answer is option 'C'. Can you explain this answer?
Which of the following gases makes bread or cake rise making them soft and spongy?
a)
CO
b)
H2
c)
CO2
d)
O2
|
Samaira nayar answered |
Explanation:
Role of Gas in Making Bread or Cake Rise:
- The gas responsible for making bread or cake rise and giving them a soft and spongy texture is carbon dioxide (CO2).
- When the dough or batter is mixed, carbon dioxide is produced through a chemical reaction.
- This gas gets trapped in the dough or batter, causing it to expand and rise during the baking process.
Yeast and Baking Powder:
- In baking, two common sources of carbon dioxide are yeast and baking powder.
- Yeast is a microorganism that ferments sugars in the dough, producing carbon dioxide as a byproduct.
- Baking powder, on the other hand, contains an acid and a base that react when mixed with liquid, releasing carbon dioxide.
Effect on Texture:
- The presence of carbon dioxide in the dough or batter creates air pockets, which expand during baking, making the bread or cake rise.
- This process results in a light, airy texture in the final product, making it soft and spongy.
Conclusion:
- Therefore, carbon dioxide plays a crucial role in the leavening process of baking by causing the dough or batter to rise and giving the bread or cake its desired texture.
Role of Gas in Making Bread or Cake Rise:
- The gas responsible for making bread or cake rise and giving them a soft and spongy texture is carbon dioxide (CO2).
- When the dough or batter is mixed, carbon dioxide is produced through a chemical reaction.
- This gas gets trapped in the dough or batter, causing it to expand and rise during the baking process.
Yeast and Baking Powder:
- In baking, two common sources of carbon dioxide are yeast and baking powder.
- Yeast is a microorganism that ferments sugars in the dough, producing carbon dioxide as a byproduct.
- Baking powder, on the other hand, contains an acid and a base that react when mixed with liquid, releasing carbon dioxide.
Effect on Texture:
- The presence of carbon dioxide in the dough or batter creates air pockets, which expand during baking, making the bread or cake rise.
- This process results in a light, airy texture in the final product, making it soft and spongy.
Conclusion:
- Therefore, carbon dioxide plays a crucial role in the leavening process of baking by causing the dough or batter to rise and giving the bread or cake its desired texture.
Gobar gas contains mainly –- a)methane
- b)ethylene
- c)propylene
- d)acetylene
Correct answer is option 'A'. Can you explain this answer?
Gobar gas contains mainly –
a)
methane
b)
ethylene
c)
propylene
d)
acetylene
|
Disha singhania answered |
Gobar gas, also known as biogas, contains mainly methane (CH4) and carbon dioxide (CO2). Methane is the primary component of biogas and is responsible for its combustible properties. Carbon dioxide is a byproduct of the anaerobic digestion process that produces biogas. In addition to methane and carbon dioxide, small amounts of other gases such as hydrogen sulfide (H2S), nitrogen (N2), and trace amounts of various impurities may also be present in gobar gas.
Which of the following is not present in German-silver?- a)Copper
- b)Nickel
- c)Silver
- d)Zinc
Correct answer is option 'C'. Can you explain this answer?
Which of the following is not present in German-silver?
a)
Copper
b)
Nickel
c)
Silver
d)
Zinc
|
|
Dia Mehta answered |
Nickel silver, also known as German silver, Argentan, new silver, nickel brass, albata, alpacca, or electrum, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named for its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th century German metalworkers in imitation of the Chinese alloy known as paktong.
When lime juice is dropped on baking soda, brisk effervescence takes place because the gas evolved is -- a)Hydrogen
- b)Oxygen
- c)Carbon dioxide
- d)All of them
Correct answer is option 'C'. Can you explain this answer?
When lime juice is dropped on baking soda, brisk effervescence takes place because the gas evolved is -
a)
Hydrogen
b)
Oxygen
c)
Carbon dioxide
d)
All of them
|
|
Eshaan Kapoor answered |
When baking soda and lemon juice are added together, the reaction of the two is an acid-based reaction because it involves an acid (citric acid in the lemon juice) reacting with a base (sodium bicarbonate, more commonly known as baking soda). Carbon dioxide, a gas, is produced by the reaction.
An emulsion is a colloid of a –- a)gas in a liquid
- b)liquid in a liquid
- c)liquid in a gas
- d)gas in a solid
Correct answer is option 'B'. Can you explain this answer?
An emulsion is a colloid of a –
a)
gas in a liquid
b)
liquid in a liquid
c)
liquid in a gas
d)
gas in a solid
|
|
Dia Mehta answered |
An emulsion is a mixture of two or more liquids that are normally immiscible (nonmixable or unblendable). Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion should be used when both the dispersed and the continuous phase are liquids. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase). Examples of emulsions include vinaigrettes, milk, mayonnaise, and some cutting fluids for metal working.
Which of the following is a natural dye?- a)Crystal violet
- b)Aniline blue
- c)Alizarin
- d)Phenolphthalein
Correct answer is option 'C'. Can you explain this answer?
Which of the following is a natural dye?
a)
Crystal violet
b)
Aniline blue
c)
Alizarin
d)
Phenolphthalein
|
|
Aryan Khanna answered |
Alizarin or 1,2-dihydroxyanthraquinone (also known as Mordant Red 11 and Turkey Red is an organic compound with formula C14H8O4 that has been used throughout history as a prominent red dye, principally for dyeing textile fabrics. Historically it was derived from the roots of plants of the madder genus. In 1869, it became the first natural pigment to be duplicated synthetically.
Gobar gas mainly contains –- a)Carbon dioxide
- b)Carbon monoxide
- c)Hydrogen sulphide
- d)Methane
Correct answer is option 'D'. Can you explain this answer?
Gobar gas mainly contains –
a)
Carbon dioxide
b)
Carbon monoxide
c)
Hydrogen sulphide
d)
Methane
|
|
Eshaan Kapoor answered |
Biogas or Lobar gas is produced by the anaerobic digestion or fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and crops. It comprises primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S), moisture and siloxanes.
Oxygen which is vital for life is a product of photosynthesis and comes from –- a)carbonates from soil
- b)carbon dioxide
- c)water
- d)oxides of mineral elements
Correct answer is option 'C'. Can you explain this answer?
Oxygen which is vital for life is a product of photosynthesis and comes from –
a)
carbonates from soil
b)
carbon dioxide
c)
water
d)
oxides of mineral elements
|
|
Eshaan Kapoor answered |
The unusually high concentration of oxygen has on Earth is the result of the oxygen cycle. This biogeochemical cycle describes the movement of oxygen within and between its three main reservoirs on Earth: the atmosphere, the biosphere, and the lithosphere. The main driving factor of the oxygen cycle is photosynthesis, which is responsible for modern Earth's atmosphere. Photosynthesis releases oxygen into the atmosphere, while respiration and decay remove it from the atmosphere.
Candle is a mixture of –- a)Paraffin wax and stearic acid
- b)Bees wax and stearic acid
- c)Higher fat acids and stearic acid
- d)Bees wax and paraffin wax.
Correct answer is option 'A'. Can you explain this answer?
Candle is a mixture of –
a)
Paraffin wax and stearic acid
b)
Bees wax and stearic acid
c)
Higher fat acids and stearic acid
d)
Bees wax and paraffin wax.
|
|
Shubhangi das answered |
Composition of a Candle:
Candles are typically made from a mixture of beeswax and paraffin wax.
Beeswax:
- Beeswax is a natural wax produced by honeybees. It is typically yellow or brown in color and has a sweet fragrance.
- Beeswax is known for its clean-burning properties and long-lasting burn time.
Paraffin Wax:
- Paraffin wax is a white or colorless soft solid derived from petroleum, coal, or shale oil.
- It is a popular choice for candle making due to its affordability, ease of use, and ability to hold color and fragrance well.
Benefits of Beeswax and Paraffin Wax Mixture:
- The combination of beeswax and paraffin wax in candles provides a balance of qualities such as clean burn, longer burn time, and good fragrance retention.
- Beeswax adds natural elements to the candle while paraffin wax helps in achieving a uniform burn.
Conclusion:
In conclusion, candles are typically made from a mixture of beeswax and paraffin wax due to the complementary properties of these two materials. This combination results in candles that burn cleanly, last longer, and hold fragrance well, making them a popular choice for various purposes.
Candles are typically made from a mixture of beeswax and paraffin wax.
Beeswax:
- Beeswax is a natural wax produced by honeybees. It is typically yellow or brown in color and has a sweet fragrance.
- Beeswax is known for its clean-burning properties and long-lasting burn time.
Paraffin Wax:
- Paraffin wax is a white or colorless soft solid derived from petroleum, coal, or shale oil.
- It is a popular choice for candle making due to its affordability, ease of use, and ability to hold color and fragrance well.
Benefits of Beeswax and Paraffin Wax Mixture:
- The combination of beeswax and paraffin wax in candles provides a balance of qualities such as clean burn, longer burn time, and good fragrance retention.
- Beeswax adds natural elements to the candle while paraffin wax helps in achieving a uniform burn.
Conclusion:
In conclusion, candles are typically made from a mixture of beeswax and paraffin wax due to the complementary properties of these two materials. This combination results in candles that burn cleanly, last longer, and hold fragrance well, making them a popular choice for various purposes.
Name the particle that is most essential to continue the chain reaction during the fission of uranium -- a)Electron
- b)Proton
- c)Neutron
- d)Positron
Correct answer is option 'C'. Can you explain this answer?
Name the particle that is most essential to continue the chain reaction during the fission of uranium -
a)
Electron
b)
Proton
c)
Neutron
d)
Positron
|
|
Faizan Khan answered |
Nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei), often producing free neutrons and photons (in the form of gamma rays), and releasing a very large amount of energy, even by the energetic standards of radioactive decay. Fission as encountered in the modern world is usually a deliberately produced manmade nuclear reaction induced by a neutron.
Ethanol containing 5% water is known as –- a)rectified spirit
- b)denatured spirit
- c)methylated alcohol
- d)power alcohol
Correct answer is option 'A'. Can you explain this answer?
Ethanol containing 5% water is known as –
a)
rectified spirit
b)
denatured spirit
c)
methylated alcohol
d)
power alcohol
|
|
Sayali nambiar answered |
Understanding Rectified Spirit
Rectified spirit refers to ethanol that has been purified through distillation, resulting in a high concentration of alcohol. When it contains 5% water, it is specifically known as rectified spirit.
Key Characteristics of Rectified Spirit:
- High Purity: Rectified spirit typically contains around 95% ethanol and 5% water, making it a highly concentrated form of alcohol.
- Uses: It is commonly used in laboratories, pharmaceuticals, and industries due to its effectiveness as a solvent and its ability to extract compounds.
- Distillation Process: The process involves distilling fermented liquids to separate alcohol from other components. This leads to the concentration of ethanol.
Comparison with Other Types of Alcohol:
- Denatured Spirit: This is ethanol that has been deliberately rendered undrinkable by adding toxic substances. It is used for industrial purposes and does not contain a specific percentage of water.
- Methylated Alcohol: This typically refers to methanol, which is highly toxic and not suitable for consumption.
- Power Alcohol: This term is used for ethanol blended with gasoline for use as fuel, usually containing more than just 5% water.
Conclusion:
The correct identification of ethanol with 5% water as rectified spirit highlights its purity and specific applications. Understanding these distinctions is crucial for fields such as chemistry and industry, making rectified spirit a valuable substance in both practical and scientific contexts.
Rectified spirit refers to ethanol that has been purified through distillation, resulting in a high concentration of alcohol. When it contains 5% water, it is specifically known as rectified spirit.
Key Characteristics of Rectified Spirit:
- High Purity: Rectified spirit typically contains around 95% ethanol and 5% water, making it a highly concentrated form of alcohol.
- Uses: It is commonly used in laboratories, pharmaceuticals, and industries due to its effectiveness as a solvent and its ability to extract compounds.
- Distillation Process: The process involves distilling fermented liquids to separate alcohol from other components. This leads to the concentration of ethanol.
Comparison with Other Types of Alcohol:
- Denatured Spirit: This is ethanol that has been deliberately rendered undrinkable by adding toxic substances. It is used for industrial purposes and does not contain a specific percentage of water.
- Methylated Alcohol: This typically refers to methanol, which is highly toxic and not suitable for consumption.
- Power Alcohol: This term is used for ethanol blended with gasoline for use as fuel, usually containing more than just 5% water.
Conclusion:
The correct identification of ethanol with 5% water as rectified spirit highlights its purity and specific applications. Understanding these distinctions is crucial for fields such as chemistry and industry, making rectified spirit a valuable substance in both practical and scientific contexts.
Chapter doubts & questions for Chemistry - RRB JE Mock Test Series for Civil Engineering (CE) 2025 2025 is part of Civil Engineering (CE) exam preparation. The chapters have been prepared according to the Civil Engineering (CE) exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Civil Engineering (CE) 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
Chapter doubts & questions of Chemistry - RRB JE Mock Test Series for Civil Engineering (CE) 2025 in English & Hindi are available as part of Civil Engineering (CE) exam.
Download more important topics, notes, lectures and mock test series for Civil Engineering (CE) Exam by signing up for free.
Signup to see your scores go up within 7 days!
Study with 1000+ FREE Docs, Videos & Tests
10M+ students study on EduRev
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up
within 7 days!
within 7 days!
Takes less than 10 seconds to signup