Equal masses of methane and hydrogen are mixed in an empty container at `25^(@)C` . The fraction of the total pressure exerted by hydrogen is :

Options

A. 16/17
B. `1//9`
C. `8//9`
D. `1//2`

Answer

C

Explanation

The pressure exerted by a gas is proportional to the number of its molecules in the container. Suppose the weight of methane and hydrogen is 16g each. Mol. Wt. of `CH_4` is 16, so, 16 g methane= N molecules of methane. Mol. Wt. of `H_2` is 2 , so, 16 g of hydrogen =16/2 =8N molecules. The total no. of molecules = N + 8N =9N . Hence , the fraction of the total pressure exerted by hydrogen =8N/9N=8/9.