MCQs for Class 10 Science Chapter 4 Carbon and Its Compounds

Carbon and Its Compounds is an important chapter in Class 10 Science that covers covalent bonding, properties of carbon, homologous series, and the reactions of carbon compounds. Practicing Carbon and Its Compounds Class 10 MCQs helps students revise key concepts, improve accuracy, and prepare for CBSE Board exams through focused objective question practice.

Students can strengthen their preparation with Class 10 Science MCQs and explore CBSE Board resources for better conceptual understanding. For revision across multiple subjects, the Class 10 MCQs collection offers chapter-wise practice, while the main MCQs section provides objective questions to support regular revision and board exam preparation.

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MCQs for Class 10 Science Chapter 4 with Answers and Explanations 

This chapter includes conceptual, reaction-based, and application-oriented questions. Before attempting MCQs, revise the core concepts carefully, especially functional groups, hydrocarbons, ethanol reactions, and soaps and detergents.

Q1. A salt sample dissolved in water does not form scum with soap. Which substance is present?

A. Magnesium chloride
B. Calcium hydrogen carbonate
C. Sodium nitrate
D. Calcium sulfate

Answer: C. Sodium nitrate
Explanation: Sodium salts do not cause hardness in water, so soap forms lather easily.

Q2. Which liquid will conduct electricity strongly?

A. Pure ethanol
B. Potassium chloride solution
C. Glucose solution
D. Solid sodium chloride

Answer: B. Potassium chloride solution
Explanation: Potassium chloride forms free ions in water, which conduct electricity.

Q3. Which reactants produce an orange-like fruity ester?

A. Ethanol and ethanoic acid
B. Octanol and ethanoic acid
C. Methanol and propanoic acid
D. Butanol and methanoic acid

Answer: B. Octanol and ethanoic acid
Explanation: Octanol and ethanoic acid form octyl acetate, which has an orange-like smell.

Q4. What is the main feature of covalent compounds?

A. High melting point
B. Soluble in water
C. Sharing of electrons
D. Formed by metals

Answer: C. Sharing of electrons
Explanation: Covalent bonds form by sharing valence electrons between atoms.

Q5. What does denatured spirit usually contain?

A. Pure ethanol
B. Ethanol with 5% methanol
C. Equal ethanol and methanol
D. Pure methanol

Answer: B. Ethanol with 5% methanol
Explanation: Methanol is added to ethanol to make it unsafe for drinking.

Q6. What byproduct is formed during soap preparation?

A. Glycerol
B. Ethylene glycol
C. Isoprene
D. Propanol

Answer: A. Glycerol
Explanation: Saponification produces soap and glycerol.

Q7. Choose the correct option.

Assertion: Soaps are biodegradable but do not work well in hard water.
Reason: Detergents clean well in hard water but are often non-biodegradable.

A. Both true and Reason explains Assertion
B. Both true but Reason does not explain Assertion
C. Assertion true, Reason false
D. Assertion false, Reason true

Answer: B
Explanation: Both statements are correct, but the reason does not explain soap failure in hard water.

Q8. What forms when sodium reacts with ethanol?

A. Sodium methoxide and hydrogen
B. Sodium ethoxide and hydrogen
C. Sodium acetate and water
D. Ethanoic acid and hydrogen

Answer: B. Sodium ethoxide and hydrogen
Explanation: Sodium reacts with ethanol to form sodium ethoxide and hydrogen gas.

Q9. Which pair are isomers?

A. Ethane and propane
B. Propane and butane
C. Butane and 2-methylpropane
D. Methane and ethane

Answer: C. Butane and 2-methylpropane
Explanation: Both have the formula C4H10 but different structures.

Q10. Functional groups mainly determine:

A. Density
B. Chemical reactivity
C. Physical state
D. Molecular mass

Answer: B. Chemical reactivity
Explanation: Functional groups decide the chemical behavior of compounds.

Q11. What is completely water-free ethanol called?

A. Rectified spirit
B. Denatured alcohol
C. Absolute alcohol
D. Power alcohol

Answer: C. Absolute alcohol
Explanation: Absolute alcohol contains almost 100% ethanol.

Q12. Which carbon allotrope conducts electricity?

A. Diamond
B. Graphite
C. Fullerene
D. Charcoal

Answer: B. Graphite
Explanation: Graphite contains free electrons that conduct electricity.

Q13. Which compound does not belong to the alkane series?

A. CH4
B. C2H6
C. C3H8
D. C4H8

Answer: D. C4H8
Explanation: C4H8 belongs to the alkene series, not alkane.

Q14. How many covalent bonds are present in ethane?

A. 6
B. 7
C. 8
D. 9

Answer: B. 7
Explanation: Ethane has 6 C-H bonds and 1 C-C bond.

Q15. Which functional group is present in butanone?

A. Carboxylic acid
B. Aldehyde
C. Ketone
D. Alcohol

Answer: C. Ketone
Explanation: The suffix '-one' indicates a ketone group.

Q16. What is the molecular formula of propane?

A. CH4
B. C2H6
C. C3H8
D. C4H10

Answer: C. C3H8
Explanation: Propane follows the alkane formula CnH2n+2.

Q17. What is the IUPAC name of acetaldehyde?

A. Ethanol
B. Ethanal
C. Methanal
D. Propanal

Answer: B. Ethanal
Explanation: Ethanal is the IUPAC name of acetaldehyde.

Q18. Why are lower alcohols soluble in water?

A. Low density
B. Volatility
C. Ion formation
D. Hydrogen bonding

Answer: D. Hydrogen bonding
Explanation: Alcohols form hydrogen bonds with water molecules.

Q19. What is the maximum number of covalent bonds carbon forms?

A. 2
B. 3
C. 4
D. 6

Answer: C. 4
Explanation: Carbon forms four covalent bonds to complete its octet.

Q20. Methane reacts with chlorine in sunlight by:

A. Addition reaction
B. Substitution reaction
C. Oxidation reaction
D. Dehydration reaction

Answer: B. Substitution reaction
Explanation: Chlorine replaces hydrogen atoms in methane.

Q21. Why does pure ethanoic acid freeze in winter?

A. High boiling point
B. Melting point near 17°C
C. Insoluble in water
D. Decomposition

Answer: B. Melting point near 17°C
Explanation: Ethanoic acid freezes around 17°C, forming ice-like crystals.

Q22. What is the formula of cyclobutane?

A. C4H10
B. C4H6
C. C4H8
D. C4H4

Answer: C. C4H8
Explanation: Cycloalkanes follow the formula CnH2n.

Q23. In a soap micelle:

1. Head dissolves in oil
   B. Both ends mix randomly
   C. Tail dissolves in oil and head faces water
   D. Tail faces water

Answer: C
Explanation: Soap tails trap oil while ionic heads remain in water.

Q24. What is the main feature of a homologous series?

A. Same density
B. Unsaturated structure
C. Difference of CH2 unit
D. Same preparation method

Answer: C. Difference of CH2 unit
Explanation: Consecutive members differ by one CH2 group.

Q25. Which formula belongs to an alkyne?

A. C6H6
B. C2H6
C. C2H4
D. C3H4

Answer: D. C3H4
Explanation: Alkynes follow the formula CnH2n-2.

Q26. What is true about ethene?

A. It has 6 hydrogen atoms
B. It contains a single bond
C. Carbon atoms share two pairs of electrons
D. Carbon atoms share three pairs of electrons

Answer: C
Explanation: Ethene contains a carbon-carbon double bond.

Q27. Which statement is correct about C60?

A. Harder than diamond
B. Soccer ball structure
C. Only hexagonal rings
D. Amorphous structure

Answer: B. Soccer ball structure
Explanation: Buckminsterfullerene has a spherical soccer-ball-like shape.

Q28. Which reagent converts ethanol into ethanoic acid?

A. Concentrated sulfuric acid
B. Alkaline potassium permanganate
C. Nickel catalyst
D. Dilute hydrochloric acid

Answer: B
Explanation: Potassium permanganate oxidizes ethanol into ethanoic acid.

Q29. What forms when ethanol is heated with concentrated sulfuric acid at 443 K?

A. Carbon dioxide
B. Ethene
C. Methane
D. Carbon

Answer: B. Ethene
Explanation: Sulfuric acid removes water from ethanol to form ethene.

Q30. What is commercial vinegar?

A. 50% ethanoic acid in alcohol
B. 5% to 8% ethanoic acid in water
C. Methanoic acid solution
D. Citric acid and ethanol mixture

Answer: B. 5% to 8% ethanoic acid in water
Explanation: Vinegar is a dilute aqueous solution of ethanoic acid.

Why This Chapter Is Important for Board Exams

Carbon and Its Compounds is one of the highest-scoring chemistry chapters in Class 10 Science. CBSE frequently asks MCQs from:

• covalent bonding
• homologous series
• functional groups
• saturated and unsaturated hydrocarbons
• ethanol and ethanoic acid reactions
• soaps and detergents

Students should focus on understanding concepts rather than memorizing definitions only.

Quick Revision Notes

Carbon Forms Covalent Bonds

Carbon shares electrons to complete its outer shell instead of gaining or losing four electrons.

Catenation

Carbon can form long chains and ring structures. This property is called catenation.

Saturated vs Unsaturated Hydrocarbons

Functional Groups

Esterification Reaction

Ethanol reacts with ethanoic acid in the presence of concentrated sulphuric acid to form an ester.

Soap Cleansing Action

Soap molecules form micelles that trap oily dirt particles and help remove them with water.

Important Exam Focus Areas

Students should revise these topics multiple times before exams:

• functional groups
• homologous series
• ethanol reactions
• ethanoic acid reactions
• saturated and unsaturated hydrocarbons
• cleansing action of soaps

Questions from these areas are commonly asked in MCQs, assertion reason, and competency-based formats.