equilibrium constant

Question 1

what is partial pressure

Answer 1

each gas’ contribution to the total pressure

Question 2

how would you calculate the partial pressure of a gas

Answer 2

partial pressure = mole fraction x total pressure

Question 3

what is the mole fraction

Answer 3

mole fraction = number of moles of gas X in mixture / total number of moles if mixture

Question 4

reaction is represented by aA + bB <–> cC
what is the Kp for the system

Answer 4

Kp = (pC^c x pD^d) / (pA^a x pB^b)

Question 5

how do you calculate units for Kp

Answer 5

units of partial pressure and cancel them out

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 for this reaction
Kp = (pC^c x pD^d) / (pA^a x pB^b)

Answer 7

pressure does not affect Kp as, if moles of gas are not the same on each side, either top or bottom of Kp expression will have a total pressure term that does not cancel

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