Densities of two gases are in the ratio 1 : 2 and their temperatures are in the ratio 2 : 1 then the ratio of their respective pressures is

Solution :
\[\begin{align} & P\propto d\,\text{and}\,T, \\ & \frac{{{P}_{1}}}{{{P}_{2}}} \\ & =\frac{{{d}_{1}}{{T}_{1}}}{{{d}_{2}}{{T}_{2}}} \\ & =\frac{1}{2}\times \frac{2}{1} \\ & \Rightarrow {{P}_{1}}:{{P}_{2}} \\ & =1:1 \\ \end{align}\]