Chemistry - Complete d-block Question with Solution | TestHub

All ${\mathrm{Cu}}^{2+}$ halides are known except the iodide. In this case, ${\mathrm{Cu}}^{2+}$ oxidises ${\mathrm{I}}^{–}$ to ${\mathrm{I}}_2$. 

$2{\mathrm{Cu}}^{2+}+4{\mathrm{I}}^{-}\to {\mathrm{Cu}}_2{\mathrm{I}}_2+{\mathrm{I}}_2$

However, many copper (I) compounds are unstable in aqueous solution and undergo disproportionation. 

$2{\mathrm{Cu}}^{+} \stackrel{}{\to } {\mathrm{Cu}}^{2+} + \mathrm{Cu}$