(i) Na + H2 → 2NaH
(ii) N2(g)+ H2(g)→ 2NH3(g)
(iii) CO + H2 \(\overset{700\,K}{\underset{Cobalt\,catalyst}{\longrightarrow}}\) CH3OH
(iv) H2(g) + Cl2(g) \(\overset{Sunlight}{\longrightarrow}\) 2HCl(g)
(v) H2 + Br2 \(\overset{Sunlight}{\longrightarrow}\) 2HBr
(vi) CuO(s) + H2 \(\overset{heat}{\longrightarrow}\) Cu + H2O