Question

A mixture of PCl5(g), PCl3(g), and Cl2(g) is in a 1.00 L reaction vessel. The total pressure of the reaction system is 1.40 atm at equilibrium. Then the volume of the reaction vessel is reduced from 1.00 L to 0.50 L and equilibrium is re-established at constant temperature. What is the total pressure of the system at this point?

Answer 1

The total pressure immediately after the volume reduction is 2.8 atmospheres

Step-by-step explanation:

The question parameters are as follows;

The initial volume of the reaction vessel, V₁ = 1.00 L

The initial pressure of the reaction system, P₁ = 1.40 atm

The final volume of the reaction system, V₂ = 0.50 L

With the assumption that the gas mixture behaves as an ideal gas, and the temperature is constant, by Boyle's law we have;

P₁·V₁ = P₂·V₂

Where;

P₁ = The initial pressure in the reaction vessel

V₁ = The initial volume in the reaction vessel

P₂ = The total final pressure in the reaction vessel after the reduction in the vessel volume

V₂ = The final volume in the reaction vessel

∴ P₂ = P₁·V₁/V₂

From which we have;

P₂ = 1.40 atm × 1.00 L/(0.50 L) = 2.8 atm

The total final pressure in the reaction vessel, P₂ = 2.8 atm.