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The s-Block Elements CBSE Class 11 MCQ & Practice Questions

Practice The s-Block Elements MCQs for CBSE Class 11 Chemistry with answers, explanations, chapter revision and related ChemNexa mock tests.

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The s-Block Elements Revision Guide for CBSE Class 11 Chemistry

The s-Block Elements is part of CBSE Class 11 Chemistry preparation. A strong revision plan should combine concept review with exam-style questions so that definitions, relationships, calculations and exceptions are recalled accurately.

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Important Topics

  • Core definitions and principles
  • Important equations or relationships
  • Common applications and examples
  • Frequently confused concepts
  • Exam-style multiple-choice questions
  • Error review and targeted revision

Revision Tip

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What to practise in The s-Block Elements

Concept Revision

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Exam-style MCQs

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Top 20 The s-Block Elements MCQs with Answers

These public questions are selected from the exact The s-Block Elements chapter, screened for topic relevance and deduplicated so repeated versions of the same MCQ are not shown publicly. Use them for quick revision, then sign in to attempt the complete test experience with more questions, results and performance review.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

1. The general valence-shell configuration of alkali metals is:

  • A. ns²
  • B. ns¹
  • C. ns²np¹
  • D. (n−1)d¹ns²
Answer: B
Explanation: Group 1 elements possess one electron in the outermost s-orbital.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

2. The general valence-shell configuration of alkaline earth metals is:

  • A. ns¹
  • B. ns²
  • C. ns²np²
  • D. (n−1)d²ns²
Answer: B
Explanation: Group 2 elements have two electrons in the outermost s-orbital.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

3. Which alkali metal has the smallest atomic radius?

  • A. Li
  • B. Na
  • C. K
  • D. Rb
Answer: A
Explanation: Atomic radius increases down Group 1, so lithium is the smallest.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

4. Which alkali metal has the lowest first ionisation enthalpy?

  • A. Li
  • B. Na
  • C. K
  • D. Cs
Answer: D
Explanation: Ionisation enthalpy decreases down the group because atomic size and shielding increase.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

5. The anomalous behaviour of lithium is mainly due to its:

  • A. Large size
  • B. Small size and high polarising power
  • C. Low charge density
  • D. Vacant d-orbitals
Answer: B
Explanation: Lithium has very small size and high charge density, causing strong polarisation.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

6. Lithium resembles magnesium because of:

  • A. Horizontal relationship
  • B. Diagonal relationship
  • C. Lanthanide contraction
  • D. Inert-pair effect
Answer: B
Explanation: Li and Mg show diagonal similarity due to comparable ionic size and charge density.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

7. Which alkali metal reacts most vigorously with water?

  • A. Li
  • B. Na
  • C. K
  • D. Cs
Answer: D
Explanation: Reactivity with water increases down Group 1 as ionisation enthalpy decreases.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

8. Alkali metals are stored under kerosene because they:

  • A. React with nitrogen only
  • B. React rapidly with air and moisture
  • C. Are insoluble in kerosene
  • D. Have high density
Answer: B
Explanation: Kerosene prevents their contact with oxygen and water vapour.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

9. Which alkali metal forms a stable nitride directly with nitrogen?

  • A. Na
  • B. K
  • C. Li
  • D. Cs
Answer: C
Explanation: Lithium forms Li₃N directly because of its small size and high lattice enthalpy.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

10. The flame colour of sodium is:

  • A. Lilac
  • B. Golden yellow
  • C. Brick red
  • D. Apple green
Answer: B
Explanation: Sodium emits an intense golden-yellow flame.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

11. The flame colour of potassium is:

  • A. Golden yellow
  • B. Lilac
  • C. Brick red
  • D. Blue-green
Answer: B
Explanation: Potassium compounds impart a lilac colour to the flame.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

12. The flame colour of calcium is:

  • A. Brick red
  • B. Lilac
  • C. Yellow
  • D. Apple green
Answer: A
Explanation: Calcium salts produce a brick-red flame.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

13. Which compound is commonly called caustic soda?

  • A. Na₂CO₃
  • B. NaOH
  • C. NaHCO₃
  • D. KOH
Answer: B
Explanation: Sodium hydroxide is known as caustic soda.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

14. Which compound is commonly called washing soda?

  • A. Na₂CO₃·10H₂O
  • B. NaHCO₃
  • C. NaOH
  • D. Na₂O₂
Answer: A
Explanation: Washing soda is sodium carbonate decahydrate.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

15. Baking soda is:

  • A. Na₂CO₃
  • B. NaHCO₃
  • C. NaOH
  • D. CaCO₃
Answer: B
Explanation: Baking soda is sodium hydrogen carbonate.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

16. On heating sodium hydrogen carbonate, the products include:

  • A. NaOH only
  • B. Na₂CO₃, CO₂ and H₂O
  • C. Na₂O and H₂
  • D. NaCl and O₂
Answer: B
Explanation: 2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

17. The Solvay process is used to manufacture:

  • A. NaOH
  • B. Na₂CO₃
  • C. KCl
  • D. CaO
Answer: B
Explanation: The ammonia-soda or Solvay process produces sodium carbonate.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

18. Which alkaline earth metal does not impart a characteristic flame colour?

  • A. Ca
  • B. Sr
  • C. Ba
  • D. Be
Answer: D
Explanation: Beryllium has high excitation energy and does not colour the flame.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

19. The solubility of Group 2 hydroxides generally:

  • A. Decreases down the group
  • B. Increases down the group
  • C. Remains constant
  • D. Becomes zero
Answer: B
Explanation: Hydration enthalpy decreases, but lattice enthalpy decreases more rapidly, so solubility increases.

CBSE Class 11 Chemistry · The s-Block Elements · Very Very Hard

20. The solubility of Group 2 sulphates generally:

  • A. Increases down the group
  • B. Decreases down the group
  • C. Remains constant
  • D. First increases then becomes infinite
Answer: B
Explanation: Hydration enthalpy decreases faster than lattice enthalpy down the group.

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The s-Block Elements Practice Tests

The s-Block Elements Frequently Asked Questions

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