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Chemistry MCQ Practice 10 — Science Foundation Course for Class 11 & 12

1. The number of moles in 25.5 g of NH₃ is:

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Correct Answer: (a) 1.5 mole

Explanation:
Molar mass NH₃ = 17 g/mol → 25.5 / 17 = 1.5 mole
2. The oxidation state of phosphorus in H₃PO₄ is:

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Correct Answer: (b) +5

Explanation:
3(+1) + x + 4(-2) = 0 → x = +5
3. The pH of 0.001 M KOH solution is:

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Correct Answer: (b) 11

Explanation:
[OH⁻] = 0.001 M → pOH = 3 → pH = 11
4. The hybridisation of oxygen in water (H₂O) is:

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Correct Answer: (c) sp³

Explanation:
Bent shape with 2 lone pairs → sp³
5. The IUPAC name of CH₃CH₂COCH₃ is:

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Correct Answer: (a) Butanone

Explanation:
Four-carbon ketone (methyl ethyl ketone)
6. The number of sigma and pi bonds in CH₃-C≡N is:

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Correct Answer: (a) 5 sigma, 2 pi

Explanation:
CH₃-C≡N → 5 σ bonds, 2 π bonds
7. The molarity of 49 g H₂SO₄ in 2 litre solution is:

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Correct Answer: (a) 0.25 M

Explanation:
Moles = 49 / 98 = 0.5, Volume = 2 L → M = 0.25
8. The element with electronic configuration [Kr] 5s² 4d¹⁰ 5p⁶ is:

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Correct Answer: (a) Xenon

Explanation:
Atomic number 54 → Xenon
9. The functional group in acid chlorides is:

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Correct Answer: (a) -COCl

Explanation:
Acid chloride group is -COCl
10. The shape of ICl₄⁻ ion is:

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Correct Answer: (b) Square planar

Explanation:
4 bond pairs + 2 lone pairs