Kerala SSLC · Chemistry · Class 10
Carbon Compounds: Important Questions with Answers
These are 10 important multiple-choice questions from the Kerala SSLC Chemistry chapter “Carbon Compounds” (Kerala SCERT syllabus). Each one shows the correct answer and a short explanation of why it is right. Try answering before you read the answer. ExamSummary has 10 practice questions on this chapter in total.
Q1.The unique ability of carbon atoms to link with one another to form long chains and rings is known as?
- A)Ionization
- B)Catenation
- C)Sublimation
- D)Polymerization
Answer: B) Catenation
This property allows carbon to form a vast variety of organic compounds by linking with itself. It is due to the strong covalent bonds formed between carbon atoms.
Q2.Which of the following represents the general formula for the homologous series of Alkenes?
- A)CnH2n+2
- B)CnH2n
- C)CnH2n-2
- D)CnHn
Answer: B) CnH2n
Alkenes contain at least one double bond between carbon atoms, reducing the hydrogen count by two compared to alkanes. Thus, the general formula is CnH2n.
Q3.What is the common name of the compound produced when ethanol reacts with ethanoic acid in the presence of concentrated sulfuric acid?
- A)Ethyl ethanoate
- B)Diethyl ether
- C)Ethylene glycol
- D)Acetaldehyde
Answer: A) Ethyl ethanoate
This reaction is called esterification, producing an ester known as ethyl ethanoate which has a fruity smell. Concentrated sulfuric acid acts as a dehydrating agent in this process.
Q4.Identify the functional group present in the molecule CH3-CH2-OH.
- A)Carboxyl group
- B)Hydroxyl group
- C)Aldehyde group
- D)Carbonyl group
Answer: B) Hydroxyl group
The -OH group attached to a carbon atom defines the alcohol family. In this molecule, the hydroxyl group makes it an alcohol.
Q5.Which chemical test is commonly used to distinguish between saturated and unsaturated hydrocarbons?
- A)Lime water test
- B)Bromine water test
- C)Red litmus paper
- D)Barium chloride solution
Answer: B) Bromine water test
Unsaturated hydrocarbons decolorize bromine water due to addition reactions across the double or triple bonds. Saturated hydrocarbons do not react with bromine water under normal conditions.
Q6.What is the primary reason soaps do not form lather in hard water?
- A)Hard water is too hot
- B)Calcium and magnesium ions form insoluble precipitates
- C)Soaps decompose instantly in minerals
- D)Hard water changes the pH drastically
Answer: B) Calcium and magnesium ions form insoluble precipitates
Hard water contains calcium and magnesium ions that react with soap molecules to form insoluble curdy white precipitates called scum. This prevents the soap from cleaning effectively until all ions are consumed.
Q7.In the saponification reaction, fats or oils react with a strong base to produce soap and what other substance?
- A)Methanol
- B)Glycerol
- C)Ethanol
- D)Acetone
Answer: B) Glycerol
Saponification involves the alkaline hydrolysis of esters found in fats. The breakdown yields sodium salts of fatty acids (soap) and glycerol as a byproduct.
Q8.What is the IUPAC name for the compound commonly known as Acetic Acid?
- A)Methanoic acid
- B)Ethanoic acid
- C)Propanoic acid
- D)Butanoic acid
Answer: B) Ethanoic acid
Acetic acid is the common name for the simplest carboxylic acid after formic acid. Its systematic IUPAC name is Ethanoic acid based on the two-carbon chain.
Q9.How many structural isomers are possible for the alkane Pentane (C5H12)?
- A)Two
- B)Three
- C)Four
- D)Five
Answer: B) Three
Pentane can exist as n-pentane, isopentane, and neopentane depending on the arrangement of the carbon chain. This demonstrates the phenomenon of isomerism in organic chemistry.
Q10.During the dehydration of ethanol to form ethene using concentrated sulfuric acid, what role does the acid play?
- A)Oxidizing agent
- B)Dehydrating agent
- C)Catalyst only
- D)Reducing agent
Answer: B) Dehydrating agent
Concentrated sulfuric acid removes water molecules from ethanol to facilitate the formation of the double bond. It acts as a strong dehydrating agent rather than just a catalyst in this specific transformation.