3.1.10 Equilibrium Constant Kp For Homogeneous Systems

Question 1

What is partial pressure?

Answer 1

Each gas’s contribution to the total pressure

Question 2

How would you calculate the partial pressure of a gas?

Answer 2

Partial pressure p = mole fraction x total pressure

Question 3

What is the mole fraction?

Answer 3

Mole fraction of gas X = number of moles of gas X in the mixture / total number of moles of gas in the mixture

Question 4

A reaction is represented by
aA (g) + bB (g) ⇌ cC (g) + dD (g)
what is Kp for the system?

Answer 4

Question 5

How do you calculate units for Kp?

Answer 5

Write out the units for the partial pressures in the same arrangement as the Kp equation and cancel out/multiply together.

Question 6

What is the effect of increasing temperature on Kp for an endothermic reaction?

Answer 6

Equilibrium shifts to the right, so partial pressures of products increase, so Kp increases

Question 7

What is the effect of increasing the overall pressure on Kp of a reaction?

Answer 7

Pressure does not affect Kp.

Question 8

What will be the kinetic effect of increasing the temperature and pressure for any reaction?

Answer 8

Increasing both will increase the rate of reaction as:
Temperature - many more particles have energy greater than or equal to the activation energy -> more successful collisions per second
Pressure - more particles in the same volume -> more successful collisions per second