\[\begin {array} {1 1} (a)\;S(rhombic)+O_2(g) \longrightarrow SO_2(g) \\ (b)\;N_2(g)+O_2(g) \longrightarrow 2NO(g) \\ (c)\;H_2(g)+ Cl_2 \longrightarrow 2HCl(g) \\ (d)\;CO(g)+\frac{1}{2} O_2(g) \longrightarrow CO_2(g) \end {array}\]
