Question

Consider a reaction A(g) → 2B(g) + C(g) Initial pressure (Pi) = 800 mm Hg. At 10 minutes, total pressure is 1600 mm Hg, then find the total pressure at 30 minutes. (in mm Hg)

Answer 1

First, we need to determine the change in pressure after 10 minutes due to the reaction.

Using the stoichiometry of the reaction, we can see that for every 1 mole of A that reacts, 2 moles of B and 1 mole of C are produced.

Let x be the amount of A that reacts in 10 minutes.

According to the reaction, 1 mole of A produces 2 moles of B and 1 mole of C, so the change in pressure = 3x.

Given that the initial pressure (Pi) is 800 mm Hg, the total pressure after 10 minutes will be Pi + change in pressure = 800 + 3x.

Given that the total pressure after 10 minutes is 1600 mm Hg, we have:
800 + 3x = 1600
3x = 1600 - 800
3x = 800
x = 800/3
x = 266.67

Total pressure after 30 minutes = Pi + change in pressure = 800 + 3*266.67
Total pressure after 30 minutes = 800 + 800
Total pressure after 30 minutes = 1600 mm Hg

Therefore, the total pressure after 30 minutes is 1600 mm Hg.