Question

Cu-CuO-CuCl2-Cu(OH)2-CuO-Cu

Answer 1

2Cu + O2 -> 2CuO

CuO + 2HCI -> CuCl2 + H2O

CuCl2 + 2NaOH -> Cu(OH)2 + 2NaCl

Cu(OH)2 -> CuO + H2O

3CuO + 2Al -> Al2O3 + 3Cu