JEE Advanced levelSingle correct optionDifficulty 3 of 3ce046
For NX2OX4(g)2NOX2(g), Kp=0.50 atm at a given temperature. Starting from pure NX2OX4, the degree of dissociation α at a total equilibrium pressure of 4.0 atm is
A0.083
B0.167
C0.333
D0.174
Answer: D
With 1 mol at the start, Kp=4α2P/(1−α2), so α2=Kp/(Kp+4P). Then α=0.50/(0.50+16.00)=0.50/16.50=0.174. At 1 atm it would be 0.333, so compression lowers α, but not in simple proportion to P.