MPTET Varg 2 Science Mock Test - 3 - MPTET MCQ

The correct answer is Water.

Key Points

Abiotic Factors:

• Abiotic factors refer to all the non-living, i.e. chemical and physical factors present in the atmosphere, hydrosphere, and lithosphere.
• Water, Sunlight, air, precipitation, minerals, and soil are some examples of abiotic factors.
• These factors have a significant impact on the survival and reproduction of species in an ecosystem.
• For instance, without an adequate amount of sunlight, autotrophic organisms may not be able to survive.
• When these organisms eventually die, it will create a shortage of food for primary consumers.
• This effect cascades up the food chain, affecting every organism. Consequently, it leads to an imbalance in the ecosystem.

Renewable resource:

• Renewable energy is energy that is produced from natural processes and continuously replenished.
• A few examples of renewable energy are sunlight, water, wind, tides, geothermal heat, and biomass. Hence, option 3 is correct.
• The energy that is provided by renewable energy resources is used in 5 important areas such as air and water cooling/heating, electricity generation, the rural sector, and transportation.
• The existence of renewable energy resources is spread over a wide geographical area in comparison to conventional energy resources which are often concentrated in a limited number of countries like oil and gas are mostly concentrated in Middle East countries.
• The use of renewable energy resources in energy generation is resulting in less pollution and has a significant effect on economic benefits and energy security.

The correct answer is distillation.

Concept:

Mixture:

• A mixture is a substance that consists of two or more elements or compounds not chemically combined together.
• For example, a mixture of salt and sand.

Separation of mixtures:

• The constituents of mixtures have different physical properties such as density, size of particles, solubility, etc.
• These differences are used to separate the constituents of the mixtures.

Explanation:

Distillation:

• It is used to separate two or more miscible liquids that have a large difference between their boiling points.

So, for separating acetone and water, distillation can be used.

Additional Information

Separating funnel: It is used to separate a mixture of two immiscible liquids, like oil and water using a separating funnel.

Chromatography:  This method is used to separate two or more dissolved solids which are present in a solution in very small quantities.

Fractional distillation: It is used to separate two or more miscible liquids that have small differences between their boiling points.

CONCEPT:

• Scattering of light: The phenomenon in which the light ray is redirected in all other directions on passing through particles of dimensions comparable to the wavelength of the light used is called scattering of light.
• The white light is consists of seven colours – violet, indigo, blue, green, yellow, orange and red.
• The wavelength of red colour light is maximum among all the seven constituent colours.

EXPLANATION:

• During morning and evening, light has to travel the farthest than during the other parts of the day to reach our eye.
• During sunset and sunrise hours, the light passing through our atmosphere to our eyes tends to be most concentrated with red light because it has maximum wavelength among all and there is almost very less scattering of red light. That’s why it looks red. Hence option 1 is correct.

The correct answer is 22.5 J.

Important Points

• Work-energy theorem: It states that the sum of work done by all the forces acting on a body is equal to the change in the kinetic energy of the body i.e., Work done by all the forces = Kf - Ki
• 
  • Where v = final velocity, u = initial velocity and m = mass of the body

CALCULATION:

Given,

Mass (m) = 5 kg

Final Velocity (v) = 3 m/s 

Initial velocity (u) = 0 m/s

According to the work-energy theorem,

⇒  Work done = Change in K.E

⇒  W = Δ K.E

Since initial speed is zero so the initial KE will also be zero.

⇒  Work done (W) = Final K.E = 1/2 mv2

⇒  W = 1/2 × 5 × 3²

⇒  W = 45/2

⇒  W = 22.5 J

The correct answer is 16th September.

Concept:

• The ozone layer is present in the stratosphere layer of the atmosphere.
• It protects the Earth from harmful ultraviolet radiation.

Explanation:

Option 1:

• World Environment Day is celebrated on 5^th June.
• It is celebrated every year on the 5^th of June for awareness and protection of the environment.

Option 2:

• National Yellow Bat Day is celebrated on the 21^st of April.
• It is celebrated to gather intelligence from the United States army.

Option 3:

• National Earth Day is celebrated on the 22^nd of April.
• It is celebrated to create awareness of the protection of the earth and its resources.

Option 4:

• World Ozone Day is celebrated on the 16^th of September.
• It was designed by United Nations General Assembly to protect the ozone layer.
• It was signed as a commemoration of the Montreal Protocol for preventing the release of ozone-depleting substances.

So, the correct answer is option 4. 

Concept:

Energy

• Energy is the capacity to do work. 
• It is neither created nor destroyed. 

Units of Energy

Joule:

• Joule is the SI unit of Energy. 

Electron volt: 

• It is the amount of energy required to move an electron from one point to another across the potential difference of 1 volt. 
• 1 electron volt = 1.602 × 10-19 Joule

Erg:

• The unit of energy expressed in centimeter-gram-second (cgs) is called erg.
• 1 erg = 10-7 J

Calorie:

• The amount of energy required to raise the temperature of 1 gram of water by 1°C or 1 Kelvin is called Calorie.
• 1 calore = 4.186 J

KwH: 

• This is a commercial unit of energy. It is the energy consumed when a device with power rating 1 Kilowatt is used for 1 hour. 

1 KwH = 3.6 × 10 6 J

Newton-meter

• Work done is said to be 1 joule, when a force of one newton actually moves a body through a distance of one meter in the direction of applied force.

Watt

• It is the work done in unit time.
• Watt is the unit of power.

Science aims at enabling students to develop their communication skills to be able to understand scientific information, such as data, ideas, arguments, and investigations, and communicate it using appropriate scientific language in a variety of communication modes.

Key Points 

Scientific Attitude: Scientific attitude is caring about evidence and being willing to change theories on the basis of new evidence.

• The scientific attitude reveals why even a failed theory can help us to understand what is special about science.
• It is the grounding of science in evidence that offers a uniquely powerful tool in the defense of science.
• Scientific attitude helps to tackle problems objectively without bias promoting logical thinking.

The Characteristics of Scientific Attitude: 

• Scientific attitude refers to critical observation, inquisitiveness, broadmindedness, and open-mindedness.
• An individual is open-mindedness, curiosity, judgment based on verified facts, ready to test and verify conclusions, faith in cause and effect relationships, collecting and reporting scientific data, critical in observations, accepting no conclusions a final or ultimate, and more faith in the books written by specialists in their respective fields, etc.
• Scientific attitude includes the following habits of thinking, the habit of accuracy in all operations, have objectivity in approach to problems, including accuracy in calculation, observation, and report.
• Scientific attitude is the combination of many qualities and virtues, which is reflected through the behavior and action of the person. 

Hence, from the above-mentioned points, it becomes clear that Hard work is not a quality of scientific attitude.

Isotopes:

• Isotopes have different physical properties and similar chemical properties.
• They are the atoms of the same element having the same numbers of protons but different numbers of neutrons.
• They have the same chemical properties due to the same electronic configuration but different physical properties.

Additional Information

The correct answer is Esters.

Key Points

• ​An ester is a chemical compound derived from an oxoacid.
• Esterification is the general name for a chemical reaction in which two reactants.
• Esters compound is obtained by the reaction of an oxoacid with a hydroxyl compound, such as alcohol or phenol
• Esters are common in Organic chemistry and biological materials.​

Additional Information

• In organic chemistry, a carbonyls group is a functional group composed of a carbon atom double-bonded to an oxygen atom.
• Amines are compounds and functional groups that contain a basic nitrogens atom with lone pair.
• A carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group.

Key Points

• Lungs are the vascularised bags that are used by the terrestrial forms for the exchange of gases (pulmonary respiration).
• Humans have a pair of lungs that are covered by a double-layered pleura or pleural membrane, with pleural fluid between them.
• It reduces friction on the lung surface.
• The outer pleural membrane is in close contact with the thoracic lining whereas the inner pleural membrane is in contact with the lung surface.

​

Additional Information

• Pericardium - The heart is protected by a double-walled membranous bag, pericardium, enclosing the pericardial fluid. 
• The peritoneum -  is the membrane that lines the visceral cavity and enclosed the visceral organs.
• Perichondrium -  is a layer of connective tissues that enclose or surrounds the cartilage of a developing bone.

Concept:

Atmospheric pressure:

• Atmospheric pressure is defined as the weight of a column of air contained in a unit area from the mean sea level to the top of the atmosphere or we can say the pressure exerted by the weight of air on the earth's surface is atmospheric pressure.
• The SI unit is millibar.
• The atmospheric pressure at sea level is 1013.2 millibar.
• The pressure of the atmosphere is measured by a mercury barometer or aneroid barometer.
• As we go at a high altitude, the pressure falls rapidly. 
• The atmospheric pressure is highest at sea level and decreases with height.

Explanation:

• The atmospheric pressure is comparatively low at high altitudes than at low altitudes because with the increase in altitude, the number of gas particles decreases, thus the collision between the gas particles also decreases. So, the pressure also decreases. 
• Whereas the atmospheric pressure is high at low altitudes at the seashore. So, the Reason is incorrect.
• At high altitudes. with the decrease in air pressure, the vapor pressure exceeds and due to the increase in vapor pressure water boils easily. Thus, the boiling temperature of water decreases. So, Assertion is also incorrect.

Therefore, from the above discussion, we can say that Both Assertions and Reason are false.

Concept:

• Introduction to the class Aves: 
• All the birds are included in the class Aves.
• Their body is boat-shaped and divided into head, neck, trunk & tail.
• Their body is covered with soft feathers called ''plumage''
• Birds are warm-blooded animals or homeothermic i.e. their temperature remains constant with respect to the outside temperature.
• They are subdivided into two sub-classes: a.) Archaeornithes b.) Neornithes

Explanation: 

• Birds have long hollow bones, filled with air cavities, these bones are called pneumatic bones.
• Pneumatic bones make the body light in weight and help in flying.

Additional Information

• Mammals have a bony endoskeleton, the skull is dicondylic. Vertebrae are acoelous or amphibian type i.e. centrum is flat at both sides. Cartilagenous pads are found at the edges of the centrum, which are called epiphysis.
• Reptiles have a chevron bone found in the caudal vertebrae.
• Osteichthyes: It is a class of fishes that has bones in their endoskeleton so they are called Bony fishes.

The Correct answer is Option Fig. 3

• The electronic dot and cross structure of ethene is: 

• As we know that, the molecular formula of Ethene is C₂H₄. Hence, the above diagram shows the correct dot and cross structure of Ethene.
• Ethylene/Ethene is an unsaturated hydrocarbon.
•  It is a colorless flammable gas with a faint sweet and musky gas.
• It is naturally produced and released by most fresh fruits and vegetables as a natural ripening agent.
• It is also known as the natural ripening hormone.

An open-ended question is one that requires thinking creatively to provide an answer or in an easy way can say those questions which helps the student to make other related questions from the asked question is open-ended.

While the close-ended question is opposite to that of an open-ended question.

• Open-ended questions can not be simply answered as yes or no or in a static response, they are like free to go through your own way.
• The answer varies from person to person.
• The open-ended question helps children to think logically and critically about the situation/problem.

Important Points

The statement" "Only open-ended questions work while teaching science" is partially correct since science is a subject where some questions can have only one answer so it doesn't always work.

Disadvantages of Open-Ended Questions

• Different answers may be received from the respondents on the same question.
• Responses can be vague, irrelevant, or not to the point.
• Many interpretations of the same question may not lead to valuable analysis.
• Coding of the responses is not possible.
• The respondent needs more time to answer.

Hence, we can conclude that no doubt open-ended questions are best in creating creativity and assessing knowledge but it is not always work in teaching science factual concepts where proof is needed.

The Correct Answer is Earth and Sun.

Key Points

An astronomical unit, often abbreviated as AU, is a unit of length that is approximately equal to the distance from the Earth to the Sun.

• It's used primarily in astronomy to describe the distances between objects in the solar system and is based on the mean distance from the center of the Earth to the center of the Sun.
• The exact definition of an astronomical unit has been refined over time as our understanding and measurements of the solar system have improved.
• As of 2012, the International Astronomical Union (IAU) defines 1 AU as exactly 149,597,870.7 kilometers, which is about 93 million miles.
• Using this standardized measure allows astronomers to express and compare distances of objects within the solar system without using very large numbers.
• For instance, one could say that Jupiter is approximately 5.2 AU from the Sun, rather than saying it is approximately 778 million kilometers away.

Additional Information

The other options provided:

• Earth and Mercury: The distance between Earth and Mercury varies greatly due to their elliptical orbits and different orbital speeds. However, it is significantly less than 1 AU.
• Earth and Moon: The distance from the Earth to the Moon is only about 0.0026 AU. This is much less than the distance from the Earth to the Sun, which defines an AU.

The correct option is Eutrophication
Key Points

• Eutrophication refers to the addition of artificial or non-artificial substances, such as nitrates and phosphates, through fertilizers or sewage, to a freshwater system.
• It can be anthropogenic or natural.
• It leads to an increase in the primary productivity of the water body or “bloom” of phytoplankton.
• The overgrowth causes the loss of oxygen in the water leading to severe reductions in fish and other animal populations.

Additional Information

• Biomagnification is the accumulation of the increasing amount ​ of non-degradable pollutants through the food chain i.e the concentration of toxicants increases at successive trophic levels. It is measured in PPM (Part Per Million).

• Global Warming: An increase in the average temperature of the earth surface due to the greenhouse effect is called global warming It also refers to the increase in the average temperature of the air and sea at the earth's surface which causes climate change

The correct answer is Cell wall.

Key Points

• The nonliving part of a tomato cell is its cell wall because the cell wall mainly constitutes nonliving cellulose.
• The cell wall forms the outer covering for the cell membrane of Bacteria, Fungi, Algae, and Plants.
• It gives the cell a definite shape.

• The plant cell wall is made up of cellulose and pectin.

• The cell wall also acts as the first line of defence against pathogens.

​Additional Information

• The Chloroplast is a double membrane-bound cell organelle.
• Out of the two membranes, the inner membrane is relatively less permeable. (the outer membrane contains porins).
• The space limited by the inner membrane is called the stroma.
• The Nucleus is a double membrane-bound dense protoplasmic body, which controls all the cellular metabolism and encloses the genetic information of the cell.
• It is considered the controller or director of the cell.
• The Cell membrane is the selectively permeable living boundary of the cell.
• It is also called Biomembrane or Plasma membrane.

Concept:

Molecule: 

The smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms. 

• S₈ is the Octasulfer molecule which has 8 Sulfer atoms.

Compound: 

A compound is a material composed of two or more components. Water, carbon dioxide, and table salt are some examples of compounds.

• O₃ is an ozone molecule, not an element the example of compounds are H₂O and CO₂.

Anion: 

A negatively charged ion is called an. 'anion' and the positively charged ion, a. 'cation'.

• N^3- is an anion because it is negatively charged.

Element: 

An element is a substance that cannot be split up into two or simpler substances by the means of chemical methods of applying heat, light, or electric energy.,

• Ag, Au, Mg, Co, etc. all are Examples of Elements.

Explanation:

(i) S8 is a molecule. - Correct

(ii) 03 is compound. - Incorrect

(iii) N3- is an anion. -  Correct

(iv) Co is an element. - Correct

Concept:

• Organisms need a constant supply of nutrients to grow, reproduce and regulate various body functions. The amount of nutrients, such as carbon, nitrogen, phosphorus, calcium, etc., present in the soil at any given time, is referred to as the standing state. It varies in different kinds of ecosystems and also on a seasonal basis.
• Nutrients are never lost from the ecosystems, rather they are recycled time and again indefinitely. The movement of nutrient elements through the various components of an ecosystem is called nutrient cycling.
• Another name of nutrient cycling is biogeochemical cycles (bio: living organism, geo rocks, air, water).
• Nutrient cycles are of two types
• Gaseous- the reservoir for the gaseous type of nutrient cycle (e.g., nitrogen, carbon cycle) exists in the atmosphere
• Sedimentary- for the sedimentary cycle (e.g., sulfur and phosphorus cycle), the reservoir is located in Earth‟s crust.
• Environmental factors, e.g., soil, moisture, pH, temperature, etc., regulate the rate of release of nutrients into the atmosphere. The function of the reservoir is to meet the deficit which occurs due to an imbalance in the rate of influx and efflux.

Explanation:

• The sulphur reservoir is in the soil and sediments where it is locked in organic (coal, oil and peat) and inorganic deposits (pyrite rock and sulphur rock) in the form of sulphates, sulphides and organic sulphur.
• It is released by weathering of rocks, erosional runoff and decomposition of organic matter and is carried to terrestrial and aquatic ecosystems in a salt solution.
• The sulphur cycle is mostly sedimentary except two of its compounds hydrogen sulphide (H2S) and sulphur dioxide (SO2) add a gaseous component to its normal sedimentary cycle.
• Sulphur enters the atmosphere from several sources like volcanic eruptions, combustion of fossil fuels, from the surface of the ocean and from gases released by decomposition. Atmospheric hydrogen sulphide also gets oxidised into sulphur dioxide.
• Atmospheric sulphur dioxide is carried back to the earth after being dissolved in rainwater as weak sulphuric acid.

Additional Information

• Carbon is a minor constituent of the atmosphere as compared to oxygen and nitrogen. However, without carbon dioxide life could not exist, because it is vital for the production of carbohydrates through photosynthesis by plants. It is the element that anchors all organic substances from coal and oil to DNA (deoxyribonucleic acid the compound that carries genetic information).
• Carbon is present in the atmosphere, mainly in the form of carbon dioxide (CO₂). The carbon cycle involves a continuous exchange of carbon between the atmosphere and organisms. Carbon from the atmosphere moves to green plants by the process of photosynthesis, and then to animals. By process of respiration and decomposition of dead organic matter returns back to the atmosphere. It is usually a short term cycle.
• Some carbon also enters a long term cycle. It accumulates as un-decomposed organic matter in the peaty layers of marshy soil or as insoluble carbonates in bottom sediments of aquatic systems which take a long time to be released.
• In deep oceans, such carbon can remain buried for millions of years till geological movement may lift these rocks above sea level. These rocks may be exposed to erosion, releasing their carbon dioxide, carbonates and bicarbonates into streams and rivers.
• Fossil fuels such as coals, oil and natural gas etc. are organic compounds that were buried before they could be decomposed and were subsequently transformed by time and geological processes into fossil fuels. When they are burned the carbon stored in them is released back into the atmosphere as carbon dioxide.

• Nitrogen is an essential constituent of protein and is a basic building block of all living tissue. It constitutes nearly 16% by weight of all the proteins that is, converted to ammonia, nitrites or nitrates before it can be taken up by plants.
• Nitrogen fixation on earth is accomplished in three different ways:
  a) By microorganisms (bacteria and blue-green algae)
  b) By man using industrial processes (fertilizer factories) and
  c) To a limited extent by atmospheric phenomena such as thunder and lighting
• Certain microorganisms are capable of fixing atmospheric nitrogen into ammonium ions. These include free-living nitrifying bacteria (e.g. aerobic Azotobacter and anaerobic Clostridium) and symbiotic nitrifying bacteria living in association with leguminous plants and symbiotic bacteria living in non-leguminous root nodule plants (e.g. Rhizobium) as well as blue-green algae (e.g. Anabaena, Spirulina).
• Ammonium ions can be directly taken up as a source of nitrogen by some plants, or are oxidized to nitrites or nitrates by two groups of specialised bacteria: Nitrosomonas bacteria promote the transformation of ammonia into nitrite. Nitrite is then further transformed into nitrate by the bacteria Nitrobacter.
• The nitrates synthesised by bacteria in the soil are taken up by plants and converted into amino acids, which are the building blocks of proteins. These then go through higher trophic levels of the ecosystem. During excretion and upon the death of all organisms nitrogen is returned to the soil in the form of ammonia.
• Certain quantities of soil nitrates, being highly soluble in water, are lost to the system by being transported away by surface run-off or groundwater. In the soil as well as oceans there are special denitrifying bacteria (e.g. Pseudomonas), which convert the nitrates/nitrites to elemental nitrogen. This nitrogen escapes into the atmosphere, thus completing the cycle.
• The periodic thunderstorms convert the gaseous nitrogen in the atmosphere to ammonia and nitrates which eventually reach the earth’s surface through precipitation and then into the soil to be utilized by plants.

Hydrogen Cycle-

• The hydrologic cycle is the continuous circulation of water in the Earth-atmosphere system which is driven by solar energy. Water on our planet is stored in major reservoirs like the atmosphere, oceans, lakes, rivers, soils, glaciers, snowfields, and groundwater. Water moves from one reservoir to another by the processes of evaporation, transpiration, condensation, precipitation, deposition, runoff, infiltration, and groundwater flow.
• Water as an important ecological factor determines the structure and function of the ecosystem. Cycling of all other nutrients is also dependent upon water as it provides their transportation during the various steps. It acts as a solvent medium for their uptake of nutrients by organisms.

CONCEPT:

• Angular velocity (ω): How fast the angular position or orientation of an object changes with time or How fast an object rotates or revolves relative to another point is known as angular velocity.
  • Angular velocity in terms of RPM (revolutions per minute) 

ω = 2 π f / 60

where ω is in terms of radian per second and f is in revolution per minute.

• Angular acceleration (α): The rate of change of angular velocity is known as angular acceleration.

The relation between α and changing ω is given by: 

ω₁ = ω₀ + α t

where ω1 is the final angular velocity, ω₀ is the initial angular velocity α is the angular acceleration.

CALCULATION:

Given that f₀ = 1800 rpm; f₁ = 3000 rpm; t = 20 sec.

ω₀ = 2 π f₀ / 60 = 2 π 1800 / 60 = 60π 

ω₁ = 2 π f₁ / 60 = 2 π 3000 / 60 = 100π 

ω1 = ω0 + α t

100π = 60π + α 20

α = 2π rad/sec²

So the correct answer is option 3.

Important Point

• Three equations to be used when α is constant

1. ω1 = ω0 + α t
2. θ = ω0t + 1/2 α t²
3. ω1² = ω0² + α t²

​where ω1 is the final angular velocity, ω₀ is the initial angular velocity, α is the angular acceleration and θ is angular displacement.

The correct answer is option 1 i.e. Strength of the intermolecular forces of attraction.

Intermolecular forces

• Intermolecular forces are the attractive and repulsive forces that arise between the molecules of a substance.
• Intermolecular forces are mainly responsible for the physical characteristics of the substance.
• The stronger the noncovalent interactions between molecules, the more energy that is required, in the form of heat, to break them apart.
• The boiling point and melting point of a substance is proportional to the strength of its non-covalent intermolecular forces i.e. the stronger the intermolecular forces, the higher the boiling point and melting point. Hence option 1 is correct.
• The strongest intermolecular force is the hydrogen bond.
• The weakest intermolecular forces are London dispersion forces.

Concept:

• Evaporation is the conversion of liquid into its vapour, below the boiling point of the liquid.
• During evaporation, a small fraction of particles at the surface, having higher kinetic energy, is able to break away from the forces of attraction of other particles and gets converted into vapour.
• Boiling is the process in which a liquid is converted into its vapour when heated to its boiling point.

Explanation:

Thus, the difference between boiling and evaporation is that evaporation can take place at any temperature while boiling cannot.

CONCEPT:

• Thrust on the top of the table is due to the weight of the wooden block. Now,
• Weight of the block,

⇒ F = mg      ...(1)

⇒ Pressure (P) = F /  A      ...(2)

Where A = Cross-section of the block touching the surface, m = Mass of the wooden block 

CALCULATION:

Given: m = 2 kg,  A = 30 cm ×10 cm = 0.30 m × 0.10 m = 0.03 m2 , Dimensions of block = 30 cm × 15 cm × 10 cm

• Using equation 1,

⇒ F = mg = 2 x 10 = 20 N

• Using equation 2,

⇒ P = 20 / 0.03 = 666.67 N/m2

So the correct answer is option 4.

Methyl Alcohol is known as a wood spirit.

• It is a chemical that has the CH₃OH formula.
• It acquired the name wood alcohol because it was once developed mainly through the destructive wood distillation.
• It is produced primarily industrial through the hydrogenation of carbon monoxide.
• It is a light, volatile, colourless, flammable liquid with a distinctive smell.

The correct answer is Positive.

Key Points

• Positive work done means that force is parallel to displacement.
• When a horse pulls a cart, it gives force in the forwarding direction.
  • If the force is enough to displace the cart, the cart will displace in the same direction as the exerted force by the horse. 
  • So the work done is positive.

Additional Information

• Negative work done means that force is opposite to displacement.
  • Example: when a positive charge is moved towards another positive charge.
• If the force is perpendicular to the displacement and if either the force or the displacement is zero, work done will be zero.
  • Example: when a coolie travels on a platform with a load on his head.

• Avogadro's number (NA) is equal to 6.022140857 × 1023.
• Avogadro's number is the no of atoms, elements or molecules present in 1 mole.
• Mass of 1 mole of substance = Atomic mass of individual

Calculation:

• Ammonia (NH₃) gas consist 17 grams per mole.
• The molecular mass of NH3 = ( 1 × 14 ) + ( 3 × 1 )
  • Molecular mass of  NH3 = 17 gm/mole
• No of Moles present in 1.7 g of ammonia given as

∴ Moles in 1.7 g of ammonia =  = 0.1 mole

The correct answer is 76 cm of Hg.
Key Points

• Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth.
• The standard atmosphere (symbol: atm) is a unit of pressure defined as 101,325 Pa (1,013.25 hPa), which is equivalent to 1013.25 millibars, 760 mm Hg, (or 76 cm Hg) 29.9212 inches Hg, or 14.696 psi.
• The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth; that is, the Earth's atmospheric pressure at sea level is approximately 1 atm.

Additional Information
Temperature Conversion Formula Table

The correct answer is Down's Syndrome.

• Down's Syndrome is caused due to an extra 21st chromosome.

Key Points

• Down's Syndrome:
  • It is also called Trisomy-21.
  • It is a chromosomal disorder caused by the presence of all or a part of an extra 21st chromosome.
  • It is associated with impairment of cognitive ability and physical growth and a particular set of facial characteristics.
  • In this syndrome, the person exhibits Mongolism.

Additional Information

• Patau's Syndrome:
  • It is also called Trisomy-13 A syndrome.
  • In this, the patient has an additional copy of autosomal chromosome 13 due to a non-disjunction of chromosomes during meiosis. i
  • Its effects are mental retardation, cut mark in the lip.
• Cri-du-Chat Syndrome:
  • It is a rare genetic disorder due to a missing part of chromosome 5.
  • It is characterized by having a cat-like cry of affected children.
• Klinefelter's Syndrome:
  • It is a condition, in which human males have an extra X-sex chromosome (44 + XXY).
  • Effects are the development of small testicles and reduced fertility.
  • Such persons are sterile males or feminized males with undeveloped testis and some feminine characteristics like enlarged breasts, etc.
  • They may be mentally retarded.

The role of a catalyst-

• The role of a catalyst in a reaction is to lower the activation energy of the reactants.
• Lowering the activation energy increases the rate of the reaction.
• The reaction now proceeds via a low energy path.
• Catalysts and promoters are also used to speed up the process and increase yield.
• For the process of hydrogenation, nickel is used as a catalyst to increase the speed of reaction.
• Unsaturated hydrocarbons add hydrogen in the presence of catalysts such as Nickel and Palladium.
• Through this process, the unsaturated hydrocarbons get converted into saturated ones.
• This process is known as an addition reaction.

Hence, the catalyst used is Nickel and Palladium for adding hydrogen to unsaturated hydrocarbons.