$ \Rightarrow \,\,{W_{{O_2}}}\, = \,\,8\,\, \times \,\,{10^{ - 3}}\,gm$

$\because \,\,S.T.P.$ એ ${\text{32}}$ ગ્રામ ${O_2}\,$ વાયુ $ = \,\,22400\,\,ml$

$\because \,\,S.T.P.\,\,$ એ ${\text{8}}\,\,{\text{1}}{{\text{0}}^{{\text{ - 3}}}}$ ગ્રામ ${O_2}\, = \,\,\,\frac{{22400\,\, \times \,\,8\,\, \times \,\,{{10}^{ - 3}}}}{{32}}\,\,ml = \,\,\,5.6\,\,ml$