Answer:
Option B,C,D
Explanation:
(b) $4CuO$ $\underrightarrow{1100^{0}C}$ $2Cu_{2}O+O_{2}$
(c) $Cu_{2}S+2Cu_{2}O$ $\underrightarrow{\triangle}$ $6Cu+SO_{2}$
$2Cu_{2}O+Cu_{2}S $ $\underrightarrow{\triangle}$ $6Cu+SO_{2}$
(d) $CuSO_{4}$ $\underrightarrow{720^{0}C}$ $CuO+SO_{2}+\frac{1}{2}O_{2}$
4CuO $\underrightarrow{1100^{0}C}$ $2Cu_{2}O+O_{2}$
$2Cu_{2}O+Cu_{2}S $ $\underrightarrow{\triangle}$ $6Cu+SO_{2}$
Reaction is believed to proceed as
$Cu_{2}S\rightleftharpoons 2Cu^{+}+S^{2-}$
$2Cu_{2}O\rightleftharpoons 4Cu^{+}+2O^{2-}$
$S^{2-}+2O^{2-}\rightarrow SO_{2}+6e^{-}$
$6Cu^{+}+6e^{-}\rightarrow 6Cu:E^{0}_{cell}=0.52$
Here, copper , sulphide is reduced to copper metal . Solidified copper has bilstered appearance due to evolution of SO2 and thus obtained copper is known as blister copper.
Other compounds which give Cu are
(i) CuO as
$4 CuO$ $\underrightarrow{1100^{0}C}$ $ 2Cu_{2}O+O_{2}$
$2Cu_{2}O+Cu_{2}S$ $\underrightarrow{\triangle}$ $6Cu+SO_{2}$
(ii) CuSO4 as
$CuSO_{4}$ $\underrightarrow{720^{0}C}$ $CuO+SO_{2}+\frac{1}{2}O_{2}$
4CuO $\underrightarrow{\triangle}$ $2Cu_{2}O+O_{2}$
$2Cu_{2}O+Cu_{2}S$ $\underrightarrow{\triangle}$ $6Cu+SO_{2}$
While CuFeS2 will not give Cu on heating . The heating in the presence of O2 gives Cu2S and FeS with the evolution of SO2
