question_answer

If \[{{M}_{1}}\,,\] \[{{M}_{2}}\,,\] \[{{M}_{3}}\] be molecular weight of constituent gases and \[{{m}_{1}},\] \[{{m}_{2}},\] \[{{m}_{3}},....\] their corresponding mass fractions, then what is the molecular weight M of the mixture equal to?

A) \[{{m}_{1}}\,{{M}_{1}}+{{m}_{2}}\,{{M}_{2}}+{{m}_{3}}\,{{M}_{3}}+...\]

B) \[\frac{1}{{{m}_{1}}\,{{M}_{1}}+{{m}_{2}}\,{{M}_{2}}+{{m}_{3}}\,{{M}_{3}}+...}\]

C) \[\frac{1}{{{m}_{1}}\,{{M}_{1}}}+\frac{1}{{{m}_{2}}\,{{M}_{2}}}+\frac{1}{{{m}_{3}}\,{{M}_{3}}}+...\]

D) \[\frac{1}{\left( \frac{{{m}_{1}}}{{{M}_{1}}} \right)+\left( \frac{{{m}_{2}}}{{{M}_{2}}} \right)+\left( \frac{{{m}_{3}}}{{{M}_{3}}} \right)+...}\]