Chemistry MCQ Practice 15 — Science Foundation Course for Class 11 & 12

1. The colligative property used to determine the molecular mass of polymers is:

(a) Osmotic pressure (b) Elevation in boiling point (c) Depression in freezing point (d) Relative lowering of vapour pressure

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Correct Answer: (a) Osmotic pressure

Explanation:
Osmotic pressure is measurable at room temperature and suitable for high molecular weight compounds like polymers

2. Which of the following is a non-stoichiometric compound?

(a) NaCl (b) FeO (c) KCl (d) H₂O

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Correct Answer: (b) FeO

Explanation:
FeO is often non-stoichiometric (Fe₀.₉₅O) due to variable oxidation state of iron

3. The coordination number and oxidation state of Cr in [Cr(H₂O)₆]Cl₃ are respectively:

(a) 6 and +3 (b) 4 and +3 (c) 6 and +6 (d) 3 and +3

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Correct Answer: (a) 6 and +3

Explanation: Cr is surrounded by 6 H₂O ligands (coordination number = 6). Oxidation state of Cr is +3 as three Cl⁻ are outside the coordination sphere.

4. Which of the following is a biodegradable polymer?

(a) Nylon-6,6 (b) Polythene (c) PHBV (d) PVC

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Correct Answer: (c) PHBV

Explanation:
Poly-β-hydroxybutyrate-co-β-hydroxyvalerate (PHBV) is a biodegradable polymer

5. The IUPAC name of the compound with structure CH₃-CH(OH)-CH₂-CH₃ is:

(a) Butan-2-ol (b) Butan-1-ol (c) 2-Methylpropan-1-ol (d) Propan-2-ol

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Correct Answer: (a) Butan-2-ol

Explanation:
Secondary alcohol with four carbons

6. Which of the following has the highest bond order?

(a) O₂ (b) O₂⁺ (c) O₂⁻ (d) O₂²⁻

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Correct Answer: (b) O₂⁺

Explanation: Bond order of O₂⁺ = 2.5 (highest among given options).

7. The vitamin whose deficiency causes scurvy is:

(a) Vitamin A (b) Vitamin B₁₂ (c) Vitamin C (d) Vitamin D

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Correct Answer: (c) Vitamin C

Explanation:
Ascorbic acid (Vitamin C) deficiency causes scurvy

8. Which of the following is a strong electrolyte?

(a) Acetic acid (b) Ammonium hydroxide (c) NaCl (d) Urea

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Correct Answer: (c) NaCl

Explanation:
NaCl completely dissociates in water

9. The monomer of natural rubber is:

(a) Styrene (b) Isoprene (c) Butadiene (d) Ethylene

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Correct Answer: (b) Isoprene

Explanation:
Natural rubber is cis-polyisoprene

10. Which of the following is an example of a zero-order reaction?

(a) Decomposition of HI on gold surface (b) Hydrolysis of ester (c) Inversion of cane sugar (d) Decomposition of N₂O₅

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Correct Answer: (a) Decomposition of HI on gold surface

Explanation:
Heterogeneous catalytic reactions on metal surfaces often follow zero order