\(Cu+2AgNO_3\rightarrow Cu\left(NO_3\right)_2+2Ag\\ Zn+2HCl\rightarrow ZnCl_2+H_2\\2 Al+3CuSO_4\rightarrow Al_2\left(SO_4\right)_3+3Cu\\ Na+H_2O\rightarrow NaOH+\dfrac{1}{2}H_2\\ Ca+\dfrac{1}{2}O_2-^{t^o}\rightarrow CaO\\ Fe+S-^{t^o}\rightarrow FeS\)