Chemistry - Complete d-block Question with Solution | TestHub

${\text{CuSO}}_{\text{4}}(\text{aq})\stackrel{{\text{H}}_{\text{2}}\text{S}}{\to }\underset{\text{Black}\text{ppt}\text{.}\text{(M)}}{\text{2CuS}}\stackrel{\text{KCN}\text{Excess}}{\to }\underset{\left(\text{N}\right)}{{{\text{[Cu(CN)}}_{\text{4}}\text{]}}^{\text{3}-}}\text{+}\underset{\left(\text{O}\right)}{{\text{(CN)}}_{\text{2}}}\uparrow$