Reversible Reactions and Dynamic Equilibrium - exam practice
Reversible Reactions and Dynamic Equilibrium
Question 1 of 3
Hydrogen has many industrial uses and can be produced from the reaction between methane and steam.
CH4(g) + H2O(g) ⇌ CO(g) + 3H2(g) ΔH = +210 kJ mol-1
Explain what would happen to the equilibrium yield of hydrogen if the pressure is increased.
Explain what would happen to the equilibrium yield of hydrogen if the temperature is increased.
A low pressure favours the production of hydrogen. In industry this reaction is carried out at a intermediate pressure of 30 atmospheres.
Suggest why this value is used.
The reaction is carried out in the presence of a nickel catalyst.
What effect does this have on the equilibrium yield of hydrogen?
A dynamic equilibrium between the gases NO2 and N2O4 is set up at room temperature. NO2 is a brown gas whereas N2O4 is a colourless gas.
2NO2(g) ⇌ N2O4(g) ΔH = -58 kJ mol-1
State two characteristics of a dynamic equilibrium.
Explain, using Le Chatelier's principle, what would be observed if the pressure was increased.
Explain, using Le Chatelier's principle, what would be observed if the reaction was carried out in a warm water bath.
Hydrogen can be prepared from the reversible reaction between methane and steam.
CH4(g) + H2O(g) ⇌ CO(g) + 3H2(g) ΔH = +210 kJ mol-1
Explain what is meant by a reversible reaction.
In industry, this reaction is carried out at a temperature of 800°C and a low pressure of 300 kPa with a nickel catalyst.
Explain, in terms of equilibrium yield and cost, why these conditions are used.
0.250 moles of CH4 and 0.250 moles of H2O are mixed together and left to reach equilibrium. The equilibrium mixture is found to contain 0.015 moles of CO.
Calculate the moles at equilibrium of CH4, H2O and H2.