Solution:
(i)
$H_{2(g)}+M_{m} O_{0(g)} \rightarrow m M_{(s)}+H_{2} O_{(l)}$
(ii)
$\mathrm{CO}_{(g)}+\mathrm{H}_{2(g)} \rightarrow \mathrm{CH}_{3} \mathrm{OH}_{(l)}$
(iii)
$\mathrm{C}_{3} \mathrm{H}_{8(g)}+3 \mathrm{H}_{2} \mathrm{O}_{(g)} \rightarrow 3 \mathrm{CO}_{(g)}+7 \mathrm{H}_{2(g)}$
(iv)
$Z n_{(g)}+N a O H_{(a q)} \rightarrow N a_{2} Z n O_{2(a q)}+H 2(g)$