is a first order reaction. The initial pressure of the system was found to be 800 mm Hg which increased to 1600 mm Hg after 10 min. The total pressure of the system after 30 min will be ____ mm Hg. (Nearest integer)
Answer: 2200
Solution
Initially, P(A) = 800 mm Hg. After 10 min, total pressure = 1600 mm Hg.
Let x mm Hg of A decompose in 10 min. Then:
P(A) = 800 - x, P(B) = 2x, P(C) = x
Total = 800 - x + 2x + x = 800 + 2x = 1600
So x = 400, meaning P(A) = 400 mm Hg after 10 min.
Since P(A) halved from 800 to 400 in 10 min, t₁/₂ = 10 min.
After 30 min (3 half-lives):
mm Hg
Amount decomposed = 700 mm Hg, producing P(B) = 1400 mm Hg and P(C) = 700 mm Hg.
Total pressure = 100 + 1400 + 700 = 2200 mm Hg.
Let x mm Hg of A decompose in 10 min. Then:
P(A) = 800 - x, P(B) = 2x, P(C) = x
Total = 800 - x + 2x + x = 800 + 2x = 1600
So x = 400, meaning P(A) = 400 mm Hg after 10 min.
Since P(A) halved from 800 to 400 in 10 min, t₁/₂ = 10 min.
After 30 min (3 half-lives):
mm Hg
Amount decomposed = 700 mm Hg, producing P(B) = 1400 mm Hg and P(C) = 700 mm Hg.
Total pressure = 100 + 1400 + 700 = 2200 mm Hg.
JEE Main · 2023 · 13 Apr 2023 · Shift 2 · Integer answer