10th class Chemistry, Chapter 22: Hydrocarbons MCQs

1. Which of the following compounds is expected to give addition reaction?

1. (A) CH₃-CH₃
2. (B) CH₂=CH₂ ✓
3. (C) CH₄
4. (D) CH₃-CH₂-CH₃

2. Which of the followings is not used as a fuel?

1. (A) LPG
2. (B) CNG
3. (C) Diesel
4. (D) Asphalt ✓

3. Indicate the type of the following reaction: CH₄ + 2O₂ → CO₂ + 2H₂O

1. (A) Substitution
2. (B) Oxidation ✓
3. (C) Reduction
4. (D) Addition

4. Which species acts as a reducing agent in the reaction between ethene and KMnO₄?

1. (A) H₂O
2. (B) CH₂=CH₂ ✓
3. (C) KMnO₄
4. (D) NaOH

5. The product which will be formed when propene reacts with bromine molecule.

1. (A) 1,2-Dibromopropane ✓
2. (B) 1,1-Dibromopropane
3. (C) 2,3-Dibromopropane
4. (D) 1,3-Dibromopropane

6. Select the name of the petroleum fraction which generates electricity in power plants.

1. (A) Bitumen
2. (B) Lubricating oil
3. (C) Kerosene oil
4. (D) Fuel oil ✓

7. The molecule eliminated in the reaction CH₃-CH₂-Br + KOH (ethanol) → CH₂=CH₂ + KBr + H₂O is:

1. (A) Br₂
2. (B) H₂
3. (C) HBr ✓
4. (D) H₂O

8. Fractional distillation of petroleum is based on:

1. (A) Viscosity
2. (B) Boiling point range ✓
3. (C) Flammability
4. (D) Melting point range

9. Alkenes are also called:

1. (A) olefins ✓
2. (B) alkynes
3. (C) aromatics
4. (D) paraffins

10. Select the general formula of the alkene family.

1. (A) CₙH₂ₙ₊₂
2. (B) CₙHₙ
3. (C) CₙH₂ₙ₋₂
4. (D) CₙH₂ₙ ✓

11. Dehydration of ethanol to ethene is carried out with:

1. (A) concentrated sulphuric acid ✓
2. (B) NaOH
3. (C) dilute HCl
4. (D) water

12. Dehydrohalogenation of alkyl halides is done with potassium hydroxide dissolved in:

1. (A) acetone
2. (B) ethanol ✓
3. (C) benzene
4. (D) water

13. Which of the following is an elimination reaction?

1. (A) Ethene + Br₂ → dibromoethane
2. (B) Ethanol → ethene + water ✓
3. (C) Ethene + H₂ → ethane
4. (D) Methane + oxygen → CO₂ + water

14. Ethylene is a plant hormone that induces:

1. (A) flowering only
2. (B) root growth
3. (C) seed loss
4. (D) ripening in fruit ✓

15. The orange pigment responsible for the colour of carrots is:

1. (A) glycol
2. (B) beta-carotene ✓
3. (C) ethylene
4. (D) acetylene

16. Cracking is carried out in the presence of ____ as catalysts.

1. (A) platinum
2. (B) nickel
3. (C) iron
4. (D) zeolites ✓

17. Cracking of alkanes is done in the ____ of oxygen.

1. (A) limited amount
2. (B) presence
3. (C) excess
4. (D) absence ✓

18. Alkenes undergo ____ reactions because of the carbon-carbon double bond.

1. (A) addition ✓
2. (B) decomposition only
3. (C) precipitation
4. (D) neutralization

19. Addition of hydrogen to alkenes in the presence of nickel is called:

1. (A) polymerization
2. (B) catalytic hydrogenation ✓
3. (C) cracking
4. (D) dehydration

20. Ethene reacts with hydrogen in the presence of nickel to give:

1. (A) ethyne
2. (B) methane
3. (C) propane
4. (D) ethane ✓