Gas-Phase Chemical Equilibrium at Constant Pressure or Constant Volume

constant pressure

constant volume

(moles of product) / (moles of reactant)

1/2

1

3/2

2

pressure (bar)

0.5

add moles of inert

0

pressure = 0.50 bar

final volume = 1.083

3

m

A ⇌ 2 B

This Demonstration calculates the number of moles at equilibrium for a gas-phase reaction

A⇌rB

at either constant pressure or constant volume. Use the buttons to select the value of

r

, either 1/2, 1, 3/2, or 2. Initially the container is filled with 5 mol of reactant

A

, and the number of moles at equilibrium is displayed in the bar graph. The height of the piston on the left is proportional to the final volume. Use sliders to set the initial pressure of

A

and the number of moles of inerts. All gases are assumed to behave ideally.