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

1. The number of moles in 12.8 g of SO₂ is:

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Correct Answer: (a) 0.2 mole

Explanation:
Molar mass SO₂ = 64 g/mol → 12.8 / 64 = 0.2 mole
2. The oxidation state of nitrogen in NH₄⁺ is:

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Correct Answer: (a) -3

Explanation:
x + 4(+1) = +1 → x = -3
3. The pH of 0.001 M acetic acid (Ka = 1.8×10⁻⁵) is approximately:

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Correct Answer: (a) 3.37

Explanation:
[H⁺] ≈ √(Ka × C) = √(1.8×10⁻⁷) ≈ 4.24×10⁻⁴ → pH ≈ 3.37
4. The hybridisation of phosphorus in PCl₅ is:

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Correct Answer: (b) sp³d

Explanation:
Trigonal bipyramidal geometry
5. The IUPAC name of CH₃CH₂CH₂CH₂CH₂OH is:

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Correct Answer: (a) Pentan-1-ol

Explanation:
Five-carbon primary alcohol
6. The number of sigma and pi bonds in CH₃-CH=CH₂ is:

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Correct Answer: (a) 8 sigma, 1 pi

Explanation:
Propene has 8 σ bonds and 1 π bond
7. The molarity of 4 g NaOH in 250 mL solution is:

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Correct Answer: (a) 0.4 M

Explanation:
Moles = 4 / 40 = 0.1, Volume = 0.25 L → M = 0.4
8. The element with electronic configuration [Ar] 3d¹⁰ 4s² is:

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Correct Answer: (b) Zn

Explanation:
Zinc (Z=30)
9. The functional group in nitro compounds is:

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Correct Answer: (a) -NO₂

Explanation:
Nitro group (-NO₂)
10. The shape of ICl₄⁻ ion is:

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Correct Answer: (b) Square planar

Explanation:
4 bond pairs + 2 lone pairs