Test: General Science (Organic Chemistry) - Software Development MCQ

The Correct Answer is Option 4 i.e Propane.

• Methane:
  • Methane is a colorless odorless gas. 
  • It is also known as marsh gas or methyl hydride. 
  • The molecular formula is CH₄.
• Pentane:
  • Pentane is found in alcoholic beverages. 
  • Pentane is present in hop oil. 
  • Pentane is any or one of the organic compounds with the formula C₅H₁₂. 
  • Its properties are very similar to those of butane and hexane.
• Propane:
  • Propane, sometimes known as liquefied petroleum gas, or LPG.
  • Propane is a three-carbon alkane gas (C₃H₈).
  • Propane is produced as a by-product of natural gas processing and crude oil refining. 
• Butane:
  • Butane is a colorless gas with a faint petroleum-like odor.
  • It is shipped as a liquefied gas under its vapor pressure. 
  • Butane is a straight-chain alkane composed of 4 carbon atoms. 
  • C₄H₁₀ is the molecular formula of butane.

Option 1 is correct, i.e. Anthracite.

• Anthracite, also called hard coal is a highly metamorphosed form of coal.
• The calorific value of a substance is defined as the amount of heat released by a unit weight of a substance during complete combustion.
• Anthracite coal has the highest calorific value.

Anthracite is a type of coal that has the highest carbon content.

• Anthracite: 87-96%
• Bituminous: 45-86%
• Lignite: 25 - 35%

Additional Information

• ​The most common volatile matter in coal is water, carbon dioxide, and sulfur dioxide.
•  Volatile matter is directly related to coal rank; as coal rank increases, volatile matter content decreases.
• Peat has the highest volatile matter.

The correct answer is Ethanol + Methanol​.

• Ethanol + Methanol​ is denatured alcohol.
• Denatured alcohol is ethanol that has additives to make it poisonous, bad-tasting, foul-smelling, or nauseating to discourage its recreational consumption.
• The term denatured alcohol refers to alcohol products adulterated with toxic and/or bad tasting additives (e.g., methanol, benzene, pyridine, castor oil, gasoline, isopropyl alcohol, and acetone), making it unsuitable for human consumption.
• The most common additive used is methanol (5–10%), giving rise to the term methylated spirits. Denatured alcohol is used as a lower-cost solvent or fuel for home-scale or industrial use.

Key Points

• Denatured alcohol is ethanol or grain alcohol that contains additional chemicals called denaturants that make it unfit for human consumption.
• Denatured alcohol is fine for some types of lab work and as an ingredient in certain products, but it's not safe to drink.
• Ethanol is an organic chemical compound. It is simple alcohol with the chemical formula C₂H₆O.
• Its formula can be also written as CH₃−CH₂−OH or C₂H₅OH and is often abbreviated as EtOH.

Additional Information

• Alcohol (ethanol or ethyl alcohol) is the ingredient found in beer, wine, and spirits that causes drunkenness.
• Alcohol is formed when yeast ferments (breaks down without oxygen) the sugars in different food. 

The correct answer is 1 i.e. propanal.

Concept:

IUPAC nomenclature:

• A systematic method of naming organic compounds.
• Naming is based on their structures.
• It is devised by the International Union of Pure and Applied chemistry.
• Many rules are followed while naming the compounds and it is different for different functional groups.
• The rules are known as IUPAC rules.

Explanation:

• This compound contains 3 carbon atoms, so its parent alkane is propane.
• It also contains an aldehyde group (-CHO-) group which is indicated by using 'al' as suffix or ending.
• So by replacing the last 'e' of butane with 'al', the name becomes propanal.
• Thus, the IUPAC name of the compound CH₃CH₂CHO is propanal.
• The common name of propanal is Propionaldehyde.

​Additional Information

• The chart for priority order and suffix name is given below:

The correct answer is Esterification.

Key Points

• Esterification -
  • Acid + Alcohol = Ester
  • It is a chemical reaction that forms at least one ester.
  • Esters are produced when acids are heated with alcohol.

Additional Information

• Crystallization -
  • The process of obtaining a pure solid in the form of crystals from a saturated solution is called crystallization.
  • In crystallization, the solution is first evaporated to separate a solid from the solution.
  • When the solution becomes very concentrated, the solution is cooled slowly by stopping evaporation, causing crystals to form.
• Saponification -
  • The saponification of a fat or oil is done by using NaOH solution for the hot process.
  • Saponification to the sodium salt of myristic acid takes place with NaOH in water.
  • Soap is formed by a chemical reaction by heating an aqueous solution of vegetable oil or fat and caustic soda or caustic potash, and glycerol is liberated.

The correct answer is Ethyl mercaptan.

Key Points

• The stench due to leakage from the LPG cylinder because of Ethyl mercaptan.
  • LPG gas is basically propane and butane.
  • It is odourless in its natural state.
  • The smell that you notice when there is a leak is actually the stench of an entirely different agent, called ethyl mercaptan​.
    • This substance is added to the gas when it leaves the main storage terminals.
• Hence, option 4 is correct.

• Methane :
  • Methane is a chemical compound with the chemical formula CH₄.
  • Methane is a one-carbon compound in which the carbon is attached by single bonds to four hydrogen atoms
  • It is a group-14 hydride and the simplest alkane and is the main constituent of natural gas.
  • It is a colourless, odourless, non-toxic but flammable gas.
  • It has a role as a fossil fuel, a member of greenhouse gas, and a bacterial metabolite.
• Butane :
  • Butane or n-butane is an alkane with the formula C₄H₁₀.
  • Butane is a gas at room temperature and atmospheric pressure.
  • Butane is a highly flammable, colourless, easily liquefied gas that quickly vaporizes at room temperature.
  • Butane is a hydrocarbon and a highly flammable, colourless, odourless, easily liquefied gas.
  • It is typically used as fuel for cigarette lighters and portable stoves, a propellant in aerosols, a heating fuel, a refrigerant.
• Propane :
  • Propane is a three-carbon alkane with the molecular formula C₃H₈.
  • It is a gas at standard temperature and pressure, but compressible to a transportable liquid. 
  • Propane is a flammable hydrocarbon gas that is liquefied through pressurization and commonly used for fuel in heating, cooling, hot water, and vehicles.
  • Propane can also be used for refrigerants, aerosol propellants, and petrochemical feedstock.​ 

The correct answer is Liver.

Key Points

• Excessive consumption of alcoholic drinks causes damage to the Liver.
  • Alcohol is readily absorbed from the digestive tract, and up to 98% is metabolised in the liver.
  • Each liver cell contains three pathways for alcohol metabolism.
  • All of these result in the production of a highly toxic metabolite which can contribute to liver cell damage.
  • With regular alcohol use, the regenerative ability of liver cells may be inhibited and lead to sustained liver damage.
  • Long term heavy alcohol use may lead to fat accumulation in the liver, which may progress to alcoholic hepatitis, or liver cirrhosis.
  • Over time, excessive alcohol use can lead to the development of chronic diseases and other serious problems including -
    • High blood pressure, heart disease, stroke, liver disease, and digestive problems. 

Additional Information

• Kidney:
  • Healthy kidneys remove wastes and extra fluid from your blood.
  • But when your kidneys fail, wastes and extra fluid can build up in your blood and make you feel sick. 
  • Kidneys can become damaged from a physical injury or a disease like diabetes, high blood pressure, or other disorders.
  • High blood pressure and diabetes are the two most common causes of kidney failure.
  • Kidney failure does not happen overnight.
• Lungs:
  • Chronic alcohol abuse and heavy drinking can greatly increase the risk of several pulmonary conditions.
    • including lung disease, alcoholic pneumonia, acute lung injury, and acute respiratory distress syndrome.
  • Smokers are more likely than nonsmokers to develop heart disease, stroke, and lung cancer.
    • Smoking can cause lung disease by damaging your airways and the small air sacs (alveoli) found in your lungs.
    • Lung diseases caused by smoking include COPD, which includes emphysema and chronic bronchitis.
• Heart:
  • Smokers are at greater risk for diseases that affect the heart and blood vessels.
  • Increases in your blood pressure can also be caused by weight gain from excessive drinking.
  • Heavy drinking weakens the heart muscle, which means the heart can't pump blood as efficiently.
    • It's is known as cardiomyopathy and can cause death, usually through heart failure.

The correct answer is Atomic Energy.

Key Points

• A biomass energy source is one that is derived from organic matter.
• The source of atomic energy is radioactive metals which are of non-organic nature and thus cannot be classified as a biomass energy source.
  

The correct answer is option 2 i.e C₄H_10.

Concept:

Hydrocarbons

• Compounds made of carbon and hydrogen atoms only are called hydrocarbons.
• Saturated hydrocarbons:
  • The hydrocarbons in which carbon atoms are singly bonded are called saturated hydrocarbons.
  • Saturated hydrocarbons are also called alkanes or paraffin.
    • The general formula of alkane– C_nH_2n+2.
• Unsaturated hydrocarbons:
  • The hydrocarbons in which carbon atoms are either doubly or triply bonded are called unsaturated hydrocarbons.
  • Doubly bonded (carbon atoms) hydrocarbons are called alkenes.
  • The general formula of alkene is C_nH₂n.

• The formula for alkane should be mentioned C_nH_2n+2

Explanation:

The correct answer is Fermentation. Key Points

• The name of the process which converts milk into curd is lactic fermentation and in this process, the lactose sugar of the milk is converted into lactic acid by lactic acid bacteria.
• The acid thus produced curdles the milk and gives it a sour taste.
• During the fermentation process, lactose fermenting bacteria utilize lactose of milk to gain energy.
• Fermentation is an enzyme-catalyzed, the metabolic process whereby organisms convert starch or sugar to alcohol or an acid anaerobically releasing energy.
• The science of fermentation is called “zymology”.
• Types of Fermentation
  • ​Homo fermentation: only one type of product formation
  • Hetero fermentation: more than one product formed
• Examples of Products Formed by Fermentation
  • ​Beer, Wine, Yogurt, Cheese, Certain sour foods containing lactic acid, including sauerkraut, kimchi, and pepperoni.
  • Bread leavening by yeast.
  • Sewage treatment.
  • Some industrial alcohol production

Additional Information