Question

What happens when:
(a) dilute sulphuric acid is poured on a copper plate?
(b) iron nails are placed in copper sulphate solution?
Write word equations of the reactions involved.

Answer 1

a) $Cu$ do not react with dilute sulphuric acid as it comes behind hydrogen in the reactivity series. But with concentrated $H_{2}S{O}_4$ it reacts to form $CuS{O}_4$ and $S{O}_2$ is evolved.

$Cu+2H_{2}S{O}_4\left(conc\right)\to CuS{O}_4+S{O}_2+2H_{2}O$

b) Since $Fe$ is more reactive than $Cu$. It will displace $Cu$ from $CuS{O}_4$ and form $FeS{O}_4$. A color change of blue to light green will occur.

$Fe+CuS{O}_4\to FeS{O}_4+Cu$