Physical - Equilibrium Constant Kp for Homogeneous Systems

Question 1

What is pressure?

Answer 1

Pressure is the force exerted by gas molecules in a particular volume.

Question 2

What is partial pressure?

Answer 2

The portion of the total pressure exerted by a single gas molecule. It is the pressure that the gas would exert if it occupied the container on its own. The sum of the partial pressures of all the gases in a mixture is the total pressure.

partial pressure of a gas = mole fraction x total pressure

Question 3

What is the mole fraction?

Answer 3

number of moles of gas / total number of moles of gas in the mixture

Question 4

How does Le Chatelier’s principle apply to gaseous equilibria?

Answer 4

Le Chatelier’s principle applies to gaseous equilibria in the same way as to equilibria in solution. The only difference is that the partial pressure of reactants and products replace concentration.

Question 5

Does pressure have an effect on the equilibrium position?

Answer 5

Changing the total pressure only affects the equilibrium position when there is a change in the total number of molecules on either side of the reaction.

Pressure will have no effect on the equilibrium position.

Question 6

What will increase the rate at which equilibrium is reached?

Answer 6

Increasing the pressure on a gas phase reaction will increase the rate at which equilibrium is reached as there will be more collisions between molecules. Increasing temperature will also increase the rate at which equilibrium is attained as will the uses of a catalyst.

Question 7

What do mole fractions all add up to?

Answer 7

1