Assertion and Reason Questions on Class 12 Chemistry Chapter 8 THE d-AND f-BLOCK ELEMENTS

Directions: These questions consist of two statements, each printed as Assertion and Reason. While answering these questions, you are required to choose any one of the following four responses.
(a) If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
(b) If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
(c) If the Assertion is correct but Reason is incorrect.
(d) If both the Assertion and Reason are incorrect.

Q.1. Assertion : Cuprous ion (Cu+) has unpaired electrons while cupric ion (Cu⁺⁺) does not.
Reason : Cuprous ion (Cu⁺) is colourless whereas cupric ion (Cu⁺⁺) is blue in the aqueous solution.

Answer

b

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Q.2. Assertion : Transition metals show variable valency.
Reason : Transition metals have a large energy difference between the ns² and (n – 1)d electrons.

Answer

c

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Q.3. Assertion : Transition metals are good catalysts.
Reason : V₂O₅ or Pt is used in the preparation of H₂SO₄ by contact process.

Answer

a

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Q.4. Assertion : Magnetic moment values of actinides are lesser than the theoretically predicted values.
Reason : Actinide elements are strongly paramagnetic

Answer

d

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