Chemistry Answers

Methanol is a very important starting material in the chemical industry. A key reaction in its

manufacture is:

CO(g) + 2H2(g) ⇌ CH3OH(g) + 52 kJ

a) Write an expression for the equilibrium constant K

i) In an equilibrium mixture at 100°C the following gas concentrations were found:

CO : 3.76 x 10-3 mol L-1 H2: 4.30 x 10-3 mol L-1

CH3OH: 4.17 x 10-10 mol L-1

Calculate the value of K(eq) at 100°C

ii) Calculate the concentration of methanol produced by the reaction in (b), with the

following reactant concentrations:

CO: 2.13 x 10-3 mol L-1

H2: 1.4 x 10-3 mol L-1

b) Define Le Chatelier’s Principle

c) Explain the effect on the equilibrium concentration of methanol if the temperature

is raised

d) A safety valve in the reaction vessel is temporarily opened to release the high

pressure gasses. Describe the effect it has on the equilibrium position and the

equilibrium constant K

Consider the exothermic reaction: A + B ⇌ C + Heat

Compare the activation energy for this reaction in the forward and reverse

directions.

Draw an energy profile diagram to illustrate your answer