Chemistry MCQ Practice 20 — Science Foundation Course for Class 11 & 12

1. The osmotic pressure of a solution is directly proportional to:

(a) Temperature (b) Molarity (c) Both temperature and molarity (d) Volume of solution

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Correct Answer: (c) Both temperature and molarity

Explanation:
π = CRT (proportional to T and C)

2. The colour of [Cu(NH₃)₄]²⁺ complex is:

(a) Blue (b) Green (c) Violet (d) Yellow

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Correct Answer: (a) Blue

Explanation:
Deep blue colour due to d-d transition

3. Which of the following is an example of addition polymer?

(a) Bakelite (b) Nylon-6,6 (c) Polythene (d) Terylene

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Correct Answer: (c) Polythene

Explanation:
Addition polymer formed from ethylene

4. The vitamin whose deficiency causes rickets is:

(a) Vitamin A (b) Vitamin D (c) Vitamin C (d) Vitamin K

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Correct Answer: (b) Vitamin D

Explanation:
Vitamin D deficiency leads to poor calcium absorption and rickets

5. The IUPAC name of CH₃-CH(CH₃)-CH₂-CH₂-CH₃ is:

(a) 2-Methylpentane (b) 3-Methylpentane (c) Hexane (d) 2,2-Dimethylbutane

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Correct Answer: (a) 2-Methylpentane

Explanation:
Longest chain of 5 carbons with methyl at position 2

6. The strongest base among the following is:

(a) NH₃ (b) CH₃NH₂ (c) (CH₃)₂NH (d) (CH₃)₃N

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Correct Answer: (c) (CH₃)₂NH

Explanation:
Secondary amine is strongest base in aqueous solution due to +I effect and solvation

7. The half-life of a second order reaction is proportional to:

(a) 1/[A]₀ (b) [A]₀ (c) [A]₀² (d) Independent of concentration

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Correct Answer: (a) 1/[A]₀

Explanation:
t₁/₂ = 1 / (k [A]₀) for second order

8. The metal extracted by electrolytic reduction is:

(a) Iron (b) Copper (c) Aluminium (d) Zinc

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Correct Answer: (c) Aluminium

Explanation:
Hall-Héroult process for aluminium

9. The monomer of Buna-S rubber is:

(a) Butadiene + Styrene (b) Butadiene + Acrylonitrile (c) Isoprene (d) Chloroprene

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Correct Answer: (a) Butadiene + Styrene

Explanation:
Buna-S is styrene-butadiene rubber

10. The enzyme that digests proteins in the stomach is:

(a) Pepsin (b) Trypsin (c) Amylase (d) Lipase

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Correct Answer: (a) Pepsin

Explanation:
Pepsin is active in acidic medium of stomach