Unit 4 Equlibria AD + PA

Question 1

What does Kc stand for?

Answer 1

Equilibrium constant

Question 2

Write the Kc expression for C2H5OH + CH3CO2H CH3CO2C2H5 + H2O

Answer 2

[CH3CO2C2H5] [H2O]
Kc = __________________
[C2H5OH] [CH3CO2H]

Question 3

What factor affects the value of Kc?

Answer 3

Temperature

Question 4

Will the equilibrium constant increase or decrease in value for a exothermic reaction when the temperature is increased?

Answer 4

The value of the equilibrium constant will decrease as the forward reaction is exothermic so an increase in temperature will cause the position of equilibrium to shift to the left decreasing the yield of products so Kc decreases as Kc = products/reactants

Question 5

By what factor will Kc increase if the concentration of N2 is doubled in the following reaction; N2 + 3H2 2NH3?

Answer 5

Kc will remain constant

Question 6

What effect does catalysts have on the value of Kc and the position of equilibrium?

Answer 6

No effect on the value of Kc and no effect on the value of the position of equilibrium

Question 7

If Kc is to the value of 10^10 what does this suggest about the reaction?

Answer 7

It would suggest that the reaction is to completion

Question 8

Write put the corresponding balanced equation to:

Kc= [A]^2[B]/[C][D]^3

Answer 8

C + 3D 2A + B

Question 9

State Le Chataliers principle?

Answer 9

Le Chataliers principle states when a system at equilibrium is disturbed, the position of equilibrium will shift in the direction that will reduce the disturbance

Question 10

what is the unit for KC in the following reaction:

3A + 2B –> C + 2D

Answer 10

mol^-2 dm^6