$(i)$ $\underset{Iron}{\mathop{3F{{e}_{(s)}}}}\,\,+\,\underset{Steam}{\mathop{4{{H}_{2}}{{O}_{(g)}}}}\,\,\to \,\underset{Iron\,(II,III)\,oxide}{\mathop{F{{e}_{3}}{{O}_{4(aq)}}}}\,\,+\underset{Hydrogen}{\mathop{\,4{{H}_{2(g)}}}}\,$

$(ii)$ $C{{a}_{(s)}}+2{{H}_{2}}{{O}_{(l)}}\to Ca{{(OH)}_{2(aq)}}$ $+{{H}_{2(g)}}+\text{ Heat }$

$(iii)$$\underset{\begin{smallmatrix} 
 \text{Calcium}\,\text{/} \\ 
 \text{Potassium} 
\end{smallmatrix}}{\mathop{2{{K}_{(s)}}}}\,+\underset{water}{\mathop{2{{H}_{2}}{{O}_{(l)}}}}\,\to \underset{\begin{smallmatrix} 
 \text{Calcium Hydroxide /} \\ 
 \text{Potassium hydroxide} 
\end{smallmatrix}}{\mathop{2KO{{H}_{(aq)}}}}\,+\underset{Hydrogen}{\mathop{{{H}_{2(g)}}}}\,+\text{ Heat }$