Chemistry - Ideal Gas Question with Solution | TestHub
At room temperature, following reaction goes to completion:
2 NO + O2 → 2 NO2 → N2O4
Dimer N2O4 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 1.2 atm. The gases are mixed by opening the stop cock. After the completion of reaction, the flasks are cooled to 200 K. Neglect the vapour pressure of dimer. (R = 0.08 l-atm/K-mol)
a = 1 (if the gas remaining at 200 K is NO) or 2 (if the gas remaining at 200 K is O2) or 3 (if the gas remaining at 200 K is NO2) or 4 (if the gas remaining at 200 K is N2O4)
bc = millimole of gas remaining at 200 K
d = 10 × the pressure (in atm) of gas remaining at 200 K.
The value of abcd is
Answer:
Solution:
n(NO) = 1.6 × 0.750/(0.08 × 300) = 50 mmol; n(O2) = 1.2 × 0.250/(0.08 × 300) = 12.5 mmol.
2 NO + O2 → N2O4: 12.5 mmol O2 consumes 25 mmol NO, leaving 25 mmol NO; the 25 mmol N2O4 formed solidifies at 200 K (vapour pressure neglected).
Gas remaining at 200 K is NO: a = 1, bc = 25.
P = nRT/V = 0.025 × 0.08 × 200/1.0 = 0.4 atm ⇒ d = 4.
abcd = 1254.
