Question

Assertion :Zinc but not copper is used for the recovery of silver from the complex $\left[Ag\right(CN{)}_2]$. Reason: Zinc is cheaper as well as a strong reducing agent than Cu and replaces Ag from the complex.

Read the above assertion and reason and choose the correct option regarding it.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

$4A{g}^{+}+8C{N}^{-}+2H_{2}O+O_2\to {\underset{\left(a\right)}{4\left[Ag\right(CN{)}_2]}}^{-}+4OH-$; $2\left[Ag\right(CN{)}_2{]}^{-}+Zn\to Ag+{\underset{\left(b\right)}{\left[Zn\right(CN{)}_4]}}^{2-}$
But $Cu$ can not be used for the recovery of silver from the complex [Ag(CN)2] because $Zn$ is cheaper as well as stronger reducing agent than $Cu$ and replaces $Ag$ from complex.