$I.$ ${Sn}-{HCl}$ $II.$ ${Sn}-{NH}_{4} {OH}$ $III.$ ${Fe}-{HCl}$ ${IV} . {Zn}-{HCl}$ $V.$ ${H}_{2}-{Pd}$ $VI.$ ${H}_{2}-$ રેની નિકલ
\((ii)\) \({Fe}+{HCl}\)
\((iii)\) \({Zn}+{HCl}\)
\((iv)\) \({H}_{2}-{Pd}\)
\((v)\) \({H}_{2}\) (Raney Ni)