Question
Question: Nitrogen tetraoxide (N₂O₄) decomposes as: N₂O₄(g) → 2NO₂(g) If the pressure of N₂O₄ falls from 0.50...
Nitrogen tetraoxide (N₂O₄) decomposes as: N₂O₄(g) → 2NO₂(g)
If the pressure of N₂O₄ falls from 0.50 atm to 0.32 atm in 30 minutes, the rate of appearance of NO₂(g) is:

A
0.006 atm min⁻¹
B
0.003 atm min⁻¹
C
0.012 atm min⁻¹
D
0.024 atm min⁻¹
Answer
0.012 atm min⁻¹
Explanation
Solution
For the reaction
\ceN2O4(g)→2NO2(g)
a drop in pressure of N₂O₄ is ΔP=0.50−0.32=0.18 atm in 30 minutes. Thus, rate of disappearance of N₂O₄:
30 min0.18 atm=0.006 atm/min.
Since,
Rate=−11dtd[\ceN2O4]=21dtd[\ceNO2],
we have the rate of appearance of NO₂:
dtd[\ceNO2]=2(0.006)=0.012 atm/min.