1.10 Equilibrium constant

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 eqn

Answer 3

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

Question 4

A reaction is
aA(g) + bB(g) <–> cC(g) + dD(g)
What is Kp for system

Answer 4

pC^c x pD^d
/
pA^a x pB^b

Pa = partial pressure of A
a= number of moles of A

Question 5

How do you calculate the 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, partial pressure of products increase so Kp increases

Question 7

What is the effect of increasing the overall pressure on Kp for this reaction

pC^c x pD^d
/
pA^a x pB^b

Answer 7

No effect as if moles of gas are not the same on each side, either top or bottom of 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 rate of reaction
Temperature - many more particles will have the activation energy, more successful collisions
Pressure - more particles in same volume - more frequent collisions