Carbon and its Compounds
Subject: General Science
Sample Practice Questions
Question 1: What is the name of the compound with the formula CH3COOH?
- Methanoic acid
- Ethanoic acid
- Propanoic acid
- Butanoic acid
Explanation: CH3COOH is ethanoic acid (acetic acid). It has two carbon atoms and belongs to the carboxylic acid homologous series.
Question 2: What is the reason for the formation of scum when soap is used with hard water?
- Soap reacts with calcium and magnesium salts
- Soap reacts with sodium chloride
- Soap reacts with carbon dioxide
- Soap reacts with oxygen
Explanation: Soap forms an insoluble precipitate (scum) with calcium and magnesium salts present in hard water. This is because the calcium and magnesium ions react with soap to form insoluble salts.
Question 3: What is the difference between consecutive members of a homologous series?
- —CH2— unit
- —CH3— unit
- —C2H5— unit
- —CH— unit
Explanation: Consecutive members of a homologous series differ by a —CH2— unit. For example, methane (CH4) and ethane (C2H6) differ by a CH2 group.
Question 4: What is the name given to the process of converting vegetable oils to fats using hydrogen?
- Hydrolysis
- Hydrogenation
- Dehydration
- Oxidation
Explanation: Hydrogenation is the process of adding hydrogen to unsaturated compounds in the presence of catalysts. Vegetable oils (unsaturated) are hydrogenated to give solid fats (saturated).
Question 5: What is the property of carbon to form bonds with other carbon atoms called?
- Tetravalency
- Catenation
- Isomerism
- Polymerisation
Explanation: Catenation is the unique ability of carbon to form bonds with other atoms of carbon, giving rise to large molecules with long chains, branched chains, or rings.
Question 6: What are compounds with identical molecular formula but different structures called?
- Homologues
- Isomers
- Polymers
- Allotropes
Explanation: Compounds with identical molecular formula but different structures are called structural isomers. For example, butane (C4H10) has two possible structures - n-butane and isobutane.
Question 7: Which functional group is present in alcohols?
- —OH
- —COOH
- —CHO
- —CO—
Explanation: The functional group present in alcohols is the hydroxyl group (—OH). For example, ethanol (C2H5OH) contains the —OH group.
Question 8: Which functional group is present in carboxylic acids?
- —OH
- —COOH
- —CHO
- —CO—
Explanation: The functional group present in carboxylic acids is the carboxyl group (—COOH). For example, ethanoic acid (CH3COOH) contains the —COOH group.
Question 9: What is the name of the compound with the formula CH3OH?
- Methanol
- Ethanol
- Propanol
- Butanol
Explanation: CH3OH is methanol (methyl alcohol). It has one carbon atom and belongs to the alcohol homologous series.
Question 10: What is the reaction between an alcohol and a carboxylic acid called?
- Saponification
- Esterification
- Hydrogenation
- Substitution
Explanation: The reaction between an alcohol and a carboxylic acid to form an ester is called esterification. For example, ethanol + ethanoic acid → ethyl acetate (ester) + water.