`A:` $CuSO_{4}$ 

`B:` $Cu(OH)_{2}$ 

`C:` $CuO$

`D:` $CuCl_{2}$

`E:` $Cu(NO_{3})_{2}$ 

Dãy `1:` $A \rightarrow B \rightarrow C \rightarrow D \rightarrow Cu$

`1.` $A \rightarrow B$: $CuSO_{4} + 2NaOH \rightarrow Cu(OH)_{2} \downarrow + Na_{2}SO_{4}$

`2.` $B \rightarrow C$: $Cu(OH)_{2} \xrightarrow{t^{o}} CuO + H_{2}O$ (phản ứng nhiệt phân)

`3.` $C \rightarrow D$: $CuO + 2HCl \rightarrow CuCl_{2} + H_{2}O$

`4.` $D \rightarrow Cu$: $CuCl_{2} + Fe \rightarrow FeCl_{2} + Cu$ (dùng kim loại mạnh đẩy kim loại yếu)

Dãy `2:` $B \rightarrow C \rightarrow A \rightarrow E \rightarrow Cu$

`1.` $B \rightarrow C$: $Cu(OH)_{2} \xrightarrow{t^{o}} CuO + H_{2}O$

`2.` $C \rightarrow A$: $CuO + H_{2}SO_{4} \rightarrow CuSO_{4} + H_{2}O$

`3.` $A \rightarrow E$: $CuSO_{4} + Ba(NO_{3})_{2} \rightarrow Cu(NO_{3})_{2} + BaSO_{4} \downarrow$

`4.` $E \rightarrow Cu$: $Cu(NO_{3})_{2} + Mg \rightarrow Mg(NO_{3})_{2} + Cu$