Assertion : Cuprous ion (Cu^+) has unpaired electrons while cupri…

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MCQ

Assertion : Cuprous ion $(Cu^+)$ has unpaired electrons while cupric ion $(Cu^{2+})$ does not.

Reason : Cuprous ion $(Cu^+)$ is colourless whereas cupric ion $(Cu^{2+})$ is blue in the aqueous solution.

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.
✓
If the Assertion is incorrect but the Reason is correct.

✓

Answer

Correct option: D.

If the Assertion is incorrect but the Reason is correct.

d
$Cu^+$ (cuprous ion) does not have any unpaired electron while cupric $(Cu^{2+})$ ion has one unpaired electron in $3d$ shell.

$C{u^ + } = 3{d^{10}}\,4{s^0}$

$C{u^{2 + }} = 3{d^9}\,4{s^0}$

Cuprous ion is colourless because it does not have any unpaired electron but $Cu^{2+}$ ion is blue in aqueous solution due to formation of complex with water molecules. So assertion is wrong but reason is true.