Class 11 Chemistry MCQ Quiz — Ch.3 & Ch.4

 

Class 11 Chemistry MCQ Quiz — Chapter 3 & Chapter 4

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Chapter 3 — Classification of Elements & Periodicity (Section A – MCQs)

1) You are given the electronic configuration: 1s² 2s² 2p⁶ 3s² 3p¹. Identify its position.

a) Period 2, Group 13 b) Period 3, Group 13 c) Period 3, Group 2 d) Period 2, Group 3

Correct answer: b) Period 3, Group 13

2) Arrange in increasing metallic character: Na, Mg, Al, Si.

a) Si < Al < Mg < Na b) Na < Mg < Al < Si c) Mg < Si < Al < Na d) Al < Na < Si < Mg

Correct answer: a) Si < Al < Mg < Na

3) Testing reactivity of Li, Na, K with water: which trend is observed?

a) K < Na < Li b) Li < Na < K c) Na < K < Li d) K < Li < Na

Correct answer: b) Li < Na < K

4) Identify the pair likely to show diagonal relationship.

a) Be and Mg b) Li and Mg c) B and Al d) Na and K

Correct answer: b) Li and Mg

5) An element X forms oxide X₂O which is strongly basic. X belongs to:

a) Group 1 b) Group 13 c) Group 15 d) Group 17

Correct answer: a) Group 1

6) In flame test, K shows violet flame while Na shows yellow. The difference is due to:

a) Different electronegativity b) Different electron configurations and energy gaps c) Their metallic nature d) Atomic size

Correct answer: b) Different electron configurations and energy gaps

7) Which pair belongs to the same period but different groups?

a) Li and Na b) C and N c) Na and Mg d) F and Cl

Correct answer: c) Na and Mg

8) Based on periodic trends, which has the highest first ionization enthalpy?

a) Li b) Na c) K d) Rb

Correct answer: a) Li

9) An element of Group 17 and Period 3 is:

a) Chlorine b) Fluorine c) Bromine d) Iodine

Correct answer: a) Chlorine

10) Which has the largest atomic radius?

a) Na b) Mg c) Al d) Si

Correct answer: a) Na

Chapter 4 — Chemical Bonding (Section A – MCQs)

11) Dry HCl gas does not turn blue litmus red, but aqueous HCl does. This indicates:

a) HCl is basic b) HCl is acidic only in presence of water c) HCl cannot form ions d) HCl is neutral

Correct answer: b) HCl is acidic only in presence of water

12) Which molecule has trigonal planar shape?

a) CO₂ b) H₂O c) BF₃ d) NH₃

Correct answer: c) BF₃

13) In diffusion of NH₃ and HCl, a white ring forms closer to the HCl jar because:

a) NH₃ is heavier and diffuses slower b) HCl is heavier and diffuses slower c) Both diffuse at same rate d) NH₄Cl is denser than both gases

Correct answer: b) HCl is heavier and diffuses slower

14) Arrange bonds in increasing polarity: C–H, C–Cl, C–F.

a) C–H < C–Cl < C–F b) C–Cl < C–F < C–H c) C–F < C–H < C–Cl d) C–H < C–F < C–Cl

Correct answer: a) C–H < C–Cl < C–F

15) In electrolysis of water, the gas collected at the cathode is:

a) Oxygen b) Nitrogen c) Hydrogen d) Carbon dioxide

Correct answer: c) Hydrogen

16) The bond angle in CH₄ is:

a) 90° b) 109.5° c) 120° d) 180°

Correct answer: b) 109.5°

17) A covalent bond is formed when:

a) One atom donates electrons to another b) Both atoms share electrons c) A metal reacts with a non-metal d) There is complete electron transfer

Correct answer: b) Both atoms share electrons

18) If the electronegativity difference > 1.7, the bond is likely:

a) Metallic b) Covalent c) Ionic d) Hydrogen

Correct answer: c) Ionic

19) A central atom with sp² hybridization will have which geometry?

a) Tetrahedral b) Trigonal planar c) Linear d) Octahedral

Correct answer: b) Trigonal planar

20) In which case is hydrogen bonding strongest?

a) NH₃ b) HF c) H₂O d) CH₄

Correct answer: b) HF