6.3

Question 1

Define the equilibrium constant, K_c. (2)

Answer 1

(1) the ratio of the conc. of products TO reactants
(2) in a reversible reaction, when dynamic equilibrium is reached

Question 2

What are the condition(s) that affect the K_c value? (1)

Answer 2

Temperature ONLY.
Not affected by catalysts or pressure or conc.

Question 3

Revise & practice how to use the K_c equation to find the value of the equilibrium constant.

Answer 3

…

Question 4

What does the size of the K_c value indicate about a reaction? (1)

Answer 4

the extent of the reaction OR the position of the equilibrium

Question 5

If the K_c value is 1, what does that indicate about the position of the equilibrium? (1)

Answer 5

the equilibrium position is halfway between the reactants and the products

Question 6

If the K_c value is greater than 1, what does that indicate about the position of the equilibrium? (1)
It shows that there’s an increase in the yield of…? (1)

Answer 6

(1) It lies to the right
(2) products

Question 7

If the K_c value is less than 1, what does that indicate about the position of the equilibrium? (1)
It shows that there’s an increase in the yield of…? (1)

Answer 7

(1) It lies to the left
(2) reactants

Question 8

What is the value of K_c for the reverse reaction? And what about the units? (2)

Answer 8

(1) It’s the reciprocal of the value for the forward reaction.
= (1/ K_c)
(2) if mol dm^-3 is the unit for the forward reaction, then the unit for the backward reaction is mol^-1 dm³