Question

Assertion : Zinc displaces copper from copper sulphate solution.
Reason : The $E^{\circ}_{298\, K}$ of $Zn$ is $-0.76 \,V$ and that of $Cu$ is $+0.34 \,V$.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (A)

$Zn(s) + Cu^2+_{(aq)} \rightarrow Zn^2+_{(aq)} + Cu_{(s)}$
$E_{Cu^{2+}/Cu}^{\circ}=0.34 V, E _{Zn/Zn}^{\circ}=-0.76 V$
Higher reduction potential of $Cu^{2+}$ ion than $Zn^{2+}$ ion shows that $Cu^{2+}$ ion has more tendency to undergo reduction.