Question

Assertion :Blue colour of $CuS{O}_4$ solution is discharged slowly when an iron rod is dipped into it. Reason: Iron is above copper in electrochemical series.

• 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

$C{u}^{2+}$ has a greater electrode reduction potential as compared to $Fe$. Therefore, when iron rod is dipped in copper sulphate solution, $C{u}^{2+}$ ions oxidize $Fe$ to $F{e}^{2+}$ ions and get reduced to $Cu$. Due to the increases in concentration of $F{e}^{2+}$ ions and decrease in $C{u}^{2+}$ concentration the blue colour of $CuS{O}_4$ fades away when an iron rod is dipped into it.

$Fe$ is more reactive than $Cu$, hence it displaces $Cu$ from $CuS{O}_4$ solution.