[Four-digit Integer] At room temperature, following reaction goes to completion: 2 + β 2 β . Dimer a β States of Matter and Gaseous State Chemistry Question
Question
[Four-digit Integer] At room temperature, following reaction goes to completion: 2 $NO$ + $O_2$ β 2 $NO_2$ β $N_2O_4$. Dimer $N_2O_4$ at 262 K is solid. A 750 ml flask and a 250 ml flask are separated by a stop cock. At 300 K, the nitric oxide in the longer flask exerts a pressure of 1.6 atm and the smaller contains oxygen at 2.4 atm. The gases are mixed by opening the stop cock. After the reaction is complete, the flasks are cooled to 200 K. Neglect the vapour pressure of dimer. If ab = gas remaining at 200 K and cd = final pressure (in atm) inside the cylinder, then the value of abcd is
π‘ Solution & Explanation
$n_{NO}=\frac{1.6\times0.75}{300R}$; $n_{O_2}=\frac{0.8\times0.25}{300R}$. Reaction $2NO+O_2\to N_2O_4$: $O_2$ is limiting. Remaining $n_{NO}=\frac{0.80}{300R}$. At 220 K, $N_2O_4$ solidifies. Total gas vol $=1$ L. $P=\frac{0.80}{300R}\times\frac{R\times220}{1}=\frac{176}{300}=0.587$ atm $=446$ mm Hg. Answer: $\boxed{0446}$