Chemistry MCQ Practice 18 — Science Foundation Course for Class 11 & 12

1. The Raoult's law is most ideal for which type of solution?

(a) Dilute solution (b) Concentrated solution (c) Solution with strong solute-solvent interaction (d) Solution showing positive deviation

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Correct Answer: (a) Dilute solution

Explanation:
Raoult's law is most accurate for dilute solutions

2. Which of the following has maximum number of unpaired electrons?

(a) Fe²⁺ (b) Mn²⁺ (c) Cr³⁺ (d) Ni²⁺

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Correct Answer: (b) Mn²⁺

Explanation:
Mn²⁺ has 5 unpaired electrons (3d⁵)

3. The complex [Co(en)₃]³⁺ shows which type of isomerism?

(a) Geometrical (b) Optical (c) Ionisation (d) Linkage

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Correct Answer: (b) Optical

Explanation:
It has non-superimposable mirror images (enantiomers)

4. Which of the following is a non-reducing sugar?

(a) Maltose (b) Sucrose (c) Lactose (d) Glucose

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Correct Answer: (b) Sucrose

Explanation:
Sucrose has no free anomeric carbon

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

(a) 2-Bromobutane (b) 1-Bromobutane (c) 3-Bromobutane (d) 2-Bromo-2-methylpropane

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Correct Answer: (a) 2-Bromobutane

Explanation:
Secondary alkyl bromide

6. The correct order of bond dissociation energy is:

(a) F₂ > Cl₂ > Br₂ > I₂ (b) Cl₂ > Br₂ > F₂ > I₂ (c) I₂ > Br₂ > Cl₂ > F₂ (d) Br₂ > Cl₂ > F₂ > I₂

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Correct Answer: (b) Cl₂ > Br₂ > F₂ > I₂

Explanation:
Cl₂ has highest bond energy due to optimal size

7. For a first order reaction, the time required for 75% completion is:

(a) t₁/₂ (b) 2 t₁/₂ (c) 3 t₁/₂ (d) 4 t₁/₂

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Correct Answer: (b) 2 t₁/₂

Explanation:
75% completion means concentration left is 25% → 2 half-lives

8. The metal extracted by Mond's process is:

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

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Correct Answer: (b) Nickel

Explanation:
Mond's process uses Ni(CO)₄ formation

9. The monomer of PVC is:

(a) Vinyl chloride (b) Ethylene (c) Styrene (d) Tetrafluoroethylene

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Correct Answer: (a) Vinyl chloride

Explanation:
PVC is polyvinyl chloride

10. The co-enzyme required for the conversion of pyruvate to acetyl CoA is:

(a) NAD⁺ (b) TPP (Thiamine pyrophosphate) (c) FAD (d) Biotin

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Correct Answer: (b) TPP (Thiamine pyrophosphate)

Explanation:
Pyruvate dehydrogenase complex requires TPP