The molar mass of ${\mathrm{N}}_2\mathrm{O}$ as well as ${\mathrm{CO}}_2$ is 44 g ${\mathrm{mol}}^{-1}$. At ${25}^{\mathrm{o}}\mathrm{C}$ and 1 atm pressure, 1 L ${\mathrm{N}}_2\mathrm{O}$ contains n molecules of gas. The number of ${\mathrm{CO}}_2$ molecules in 2 L under same conditions will be: