Carbon and Its Compounds 50 MCQs with Answers | Class 10 Chemistry by Sadre Alam

Carbon and Its Compounds – 50 MCQs with Answers

Carbon and its compounds form the foundation of organic chemistry and are an important chapter for Class 10 board examinations. In this post, you will find 50 carefully selected multiple choice questions (MCQs) with correct answers based on the latest syllabus. These MCQs will help students understand key concepts such as covalent bonding, hydrocarbons, functional groups, ethanol, ethanoic acid, soaps and detergents, and polymers. This resource is ideal for revision, practice tests, and exam preparation.

1. What is the atomic number of carbon?

A. 4

B. 6

C. 8

D. 12

Answer B  (6)

2. What is the valency of carbon?

A. 2

B. 3

C. 4

D. 6

Answer C (4)

3. Which of the following is an allotrope of carbon?

A. Salt

B. Diamond

C. Quartz

D. Limestone

Answer B (Diamond)

4. Diamond is a —- substance.

A. Soft

B. Good conductor

C. Hardest

D. Liquid

Answer C (Hardest)

5. Graphite is a good conductor of

A. Heat

B. Electricity

C. Sound

D. Light

Answer B (Electricity)

6. The ability of carbon to form long chains is called

A. Isomerism

B. Homologous series

C. Covalency

D. Catenation

Answer D (Catenation)

7. Which of the following is a saturated hydrocarbon?

A. Ethene

B. Ethyne

C. Methane

D. Benzene

Answer C (Methane)

8. Unsaturated hydrocarbons contain

A. Single bonds only

B. Double or triple bonds

C. Ionic bonds

D. Hydrogen bonds

Answer B (Double or triple bonds)

9. The molecular formula of ethene is

A. C₂H₆

B. C₂H₄

C. C₂H₂

D. CH₄

Answer B (C₂H₄)

10. The general formula of alkanes is

A. CnH2n

B. CnH2n+2

C. CnH2n−2

D. CnHn

Answer B (CnH2n+2)

11. The common name of ethanol is

A. Vinegar

B. Alcohol

C. Kerosene

D. Petrol

Answer B (Alcohol)

12. The chemical formula of ethanol is

A. CH₃COOH

B. C₂H₅OH

C. CH₄

D. C₂H₆

Answer B (C₂H₅OH)

13. The chemical formula of acetic acid is

A. C₂H₅OH

B. HCOOH

C. CH₃COOH

D. COOH

Answer C (CH₃COOH)

14. Vinegar is

A. Pure acid

B. Aqueous solution of acetic acid

C. A base

D. A salt

Answer B

15. Soaps are sodium or potassium salts of

A. Mineral acids

B. Carboxylic acids

C. Alcohols

D. Aldehydes

Answer B (Carboxylic acids)

16. Detergents work well in

A. Soft water only

B. Hard water only

C. Both soft and hard water

D. Sea water only

Answer C Both Soft and hard water 

17. Soap does not form lather in hard water due to the presence of

A. Na⁺ ions

B. Ca²⁺ and Mg²⁺ ions

C. H⁺ ions

D. Cl⁻ ions

Answer B (Ca²⁺ and Mg²⁺ ions)

18. The functional group –COOH represents

A. Alcohol

B. Aldehyde

C. Carboxylic acid

D. Ketone

Answer C (Carboxylic acid)

19. The –OH functional group is called

A. Aldehyde

B. Alcohol

C. Ketone

D. Acid

Answer B (Alcohol)

20. Isomerism means

A. Same formula, different structures

B. Different formula, same properties

C. Same colour

D. Same state

Answer A (Same formula, different structures)

21. The molecular formula of benzene is

A. C₆H₆

B. C₆H₁₂

C. C₅H₆

D. C₆H₁₄

Answer A (C₆H₆)

22. Carbon compounds usually have low melting points because they are

A. Ionic

B. Covalent

C. Metallic

D. Hydrogen bonded

Answer B Covalent

23. Which of the following is a bio-fuel?

A. Coal

B. Petrol

C. Ethanol

D. Diesel

Answer C (Ethanol)

24. The general formula of alkynes is:

A. CnH2n

B. CnH2n+2

C. CnH2n−2

D. CnHn

Answer C (CnH2n−2)

25. Heating ethanol with concentrated H₂SO₄ produces

A. Ethene

B. Ethane

C. Acetic acid

D. Methane

Answer A  (Ethene)

26. The purest form of carbon is

A. Coke

B. Charcoal

C. Diamond

D. Graphite

Answer C (Diamond)

27. Petroleum is separated by

A. Simple distillation

B. Fractional distillation

C. Filtration

D. Crystallisation

Answer B (Fractional distillation)

28. The main component of LPG is

A. Methane

B. Ethane

C. Propane and butane

D. Ethene

Answer C (Propane and butane)

29. Carbon monoxide is

A. Poisonous gas

B. Inert gas

C. Basic gas

D. Useful gas

Answer A (Poisonous gas)

30. Carbon dioxide is used in

A. Respiration

B. Fire extinguishers

C. Cooking

D. Welding

Answer B (Fire extinguishers)

31. The test used to detect ethanol is

A. Sodium test

B. Iodoform test

C. Copper sulphate test

D. Litmus test

Answer B (Iodoform test)

32. How many important isotopes of carbon are there?

A. 2

B. 3

C. 4

D. 5

Answer B (3)

33. Carbon-14 is used for

A. Fuel

B. Cancer treatment

C. Age determination

D. Fertilisers

Answer C (Age determination)

34. Covalent compounds are generally

A. Soluble in water

B. Insoluble in water

C. Highly soluble

D. Strong electrolytes

Answer B (Insoluble in water)

35. Most carbon compounds are

A. Ionic

B. Covalent

C. Metallic

D. Electrovalent

Answer B (Covalent)

36. The cleansing action of soap is based on

A. Neutralisation

B. Emulsification

C. Precipitation

D. Decomposition

Answer B (Emulsification)

37. Detergents are prepared from

A. Natural fats and oils

B. Petrochemicals

C. Coal

D. Wood

Answer B (Petrochemicals)

38. The functional group of aldehydes is

A. –COOH

B. –OH

C. –CHO

D. –CO–

Answer C (–CHO)

39. The functional group of ketones is

A. –CO–

B. –CHO

C. –COOH

D. –OH

Answer A (–CO–)

40. Which of the following is NOT a carbon compound?

A. CO₂

B. Na₂CO₃

C. CaCO₃

D. NaCl

Answer D (NaCl)

41. Methane is mainly used as

A. Fuel

B. Fertiliser

C. Medicine

D. Plastic

Answer A (Fuel)

42. Plastics are mainly made of

A. Metals

B. Polymers

C. Salts

D. Acids

Answer B (Polymers)

43. PVC stands for

A. Poly Vinyl Carbon

B. Poly Vinyl Chloride

C. Poly Vinyl Compound

D. Poly Vinyl Carbonate

Answer B (Poly Vinyl Chloride)

44. An example of thermoplastic is

A. Bakelite

B. Melamine

C. Polythene

D. Phenol

Answer C (Polythene)

45. An example of thermosetting plastic is

A. PVC

B. Polythene

C. Bakelite

D. Nylon

Answer C (Bakelite)

46. Nylon is a

A. Natural polymer

B. Synthetic polymer

C. Metal

D. Salt

Answer B (Synthetic polymer)

47. Which is a biodegradable substance?

A. Plastic

B. Polythene

C. Paper

D. PVC

Answer C (Paper)

48. The study of carbon compounds is called

A. Inorganic chemistry

B. Physical chemistry

C. Organic chemistry

D. Nuclear chemistry

Answer C (Organic chemistry)

49. A covalent bond is formed by

A. Transfer of electrons

B. Loss of electrons

C. Sharing of electrons

D. Sharing of protons

Answer C (Sharing of electrons)

50. Carbon is the basis of life because of

A. High atomic mass

B. Catenation and variety of compounds

C. Metallic nature

D. Gaseous nature

Answer B (Catenation and variety of compounds)