At equilibrium at a particular temperature, 10% of the 2-propanol is converted to propanone - VCE - SSCE Chemistry - Question 6 - 2007 - Paper 1

To understand how to increase the yield of propanone at equilibrium, we can analyze the effects of temperature and pressure based on Le Chatelier's principle, especially considering that the reaction is exothermic with ΔH = -54 kJ mol⁻¹.

1. Effect of Temperature: Since the reaction is exothermic, lowering the temperature favored the formation of products. Therefore, to shift the equilibrium towards propanone, lowering the temperature is advisable.

2. Effect of Pressure: The reaction involves a change in the number of moles of gas: 1 mole of 2-propanol (reactant) is converted to 1 mole of propanone (product). This means that pressure has no significant impact on the position of the equilibrium in this case. Thus, pressure changes would not significantly shift the equilibrium in favor of propanone.

Given these considerations, the best option to increase the yield of propanone at equilibrium is:

A. lower the temperature and raise the pressure. This will shift equilibrium to favor product formation even further.