Equilibrium I

Question 1

Define the term dynamic equilibrium.

Answer 1

The rate of the forward reaction is equal to the
rate of the reverse reaction.
(Hence, the concentrations of reactants and products do not
change.)

Question 2

Give an essential condition
for an equilibrium mixture.

Answer 2

Equilibrium occurs in a closed system where
reactants and products cannot escape.

Question 3

State Le Chatelier’s
principle

Answer 3

If a system at equilibrium is altered, the
position of equilibrium moves in the
direction that reduces the effect of the
initial change.

Question 4

What happens when temperature increased when forward is endo thermic

Answer 4

Shifts to the right

Question 5

What happens when pressure is increased

Answer 5

Favours the side with fewer moles of gas

Question 6

Why would you use high pressure in a reaction

Answer 6

The high pressure increases the collision frequency,
increasing the rate of reaction.
2. This is a compromise pressure between an economically
viable rate of reaction and a slightly lower yield of hydrogen
from the equilibrium reaction.

Question 7

What effect does a catalyst
have on the position of
equilibrium

Answer 7

No effect because catalysts effect both forward and backwards queally

Question 8

What conditions affects Kc

Answer 8

Temp

Question 9

How do you make an expression for Kc

Answer 9

[A]^a * [B]^b / [C]^c x [D]^d

Question 10

What type of system is K c
relevant for?

Answer 10

Homogeneous systems in
equilibrium

Question 11

What does K c being greater
or less than 1 suggest for
the position of equilibrium?

Answer 11

Greater than 1 = shifted to the right
Lesser than 1 = shifted to the left

Question 12

What effect does decreasing the
temperature in an endothermic
reaction
have on K c ?

Answer 12

K c decreases
(The endothermic reaction isn’t favoured so equilibrium shifts
to the left.)

Question 13

What effect does increasing the
temperature in an endothermic
reaction have on Kc ?

Answer 13

K c increases
(The endothermic reaction is favoured so equilibrium shifts to
the right

Question 14

What effect does decreasing the
temperature in an exothermic
reaction have on K c ?

Answer 14

K c increases
(The exothermic reaction is favoured so equilibrium shifts to
the right.)

Question 15

What effect does increasing the
temperature in an exothermic
reaction have on K c

Answer 15

K c decreases
(The exothermic reaction isn’t favoured so equilibrium shifts
to the left.)

Question 16

What does changing the Concentration do to Kc

Answer 16

Nothing

So equillibrium moves to restore Q=Kc