The effect of concentration

3 marks · Easy

Methanol (3e{CH3OH}) is produced in industry by the following equilibrium:

A technician increases the concentration of hydrogen gas (62e{H2}).

(a)

State the effect on the position of equilibrium.

[1 mark]

(b)

Explain your answer in (a).

[2 marks]

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(a) Equilibrium shifts to the right (towards CH3OH).

(b) Increasing H2 concentration causes the system to use it up by reacting more CO and H2 to produce more CH3OH, so the equilibrium shifts to the right to produce more product.

Show mark scheme and worked solution

Marking points

A1 (a) · 1 mark · States position shifts right/towards CH3OH.

M1 (b) · 1 mark · Explains system reacts to use up extra H2 (refers to using reactants/making more product).

A2 (b) · 1 mark · Links to equilibrium shifting right/producing more CH3OH as response.

Worked solution

a) The position shifts to the right, towards CH3OH.

b) When H2 is increased, the system reacts more CO and H2 to use up the added H2, producing more CH3OH. This is Le Chatelier's principle.