At $0^{\circ}$, the density of carbon-di-oxide is the same as that of an oxide of nitrogen. The oxide of nitrogen is which of the following, considering the pressure conditions to be the same?

Question

(A) $NO_2$ (B) $N_2O$ (C) $NO$ (D) $N_2O_2$

Answer 1

For any ideal gas, denity $\rho = \large\frac{PM}{RT}$

For density to be equal at equal temperatures, mass of the gases needs to be the same.

Molecular mass of $CO_2 = 44 = $ molar mass of $N_2O \rightarrow $ this must be the oxide with the same density as $CO_2$.