Question

A gaseous mixture contains oxygen and nitrogen in the ratio of 1:8 by mass. The ratio of their respective number of molecules $(N_{O_2}:N_{N_2})$ is x:y
Calculate x+y

Answer 1

Given,
mass ratio
$(m_{O_2}:m_{N_2})=1/8$
mole ratio
$(n_{O_2}:n_{N_2})=\frac{1/32}{8/28}=7/64$
so molecules ratio
$(N_{O_2}:N_{N_2})=7/64$
so x+y = $71$.