1.1. Ethanol has a great number of uses. For industrial purposes, it can be manufactured via the following reversible reaction.

C₂H₄ (g) + H₂O (g) ⇋ C₂H₅OH (g)

ΔH = -46 kJ mol^-1

The optimum pressure for this reaction is between 60 and 70 atm.  

Using Le Chatelier’s principle, state and explain the effect, if any, that increasing the overall pressure would have on the equilibrium yield of ethanol.

1.2. Although Le Chatelier’s principle is used to suggest the best conditions for a reaction, often a compromise has to be made.

i) Use Le Chatelier’s principle to suggest whether a high or low temperature should be used to produce the maximum yield of ethanol in the reaction from part (a).

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ii) State a problem that may occur from using this temperature.

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1.3. Ethanol can be used as a reactant in another equilibrium reaction; the manufacture of ethyl ethanoate. 

CH₃CH₂OH (l) + CH₃COOH (l) ⇋ CH₃COOCH₂CH₃ (l) + H₂O (l) 

Give the expression for the equilibrium constant, K_c, for this equilibrium.

1.4. A student set up the esterification reaction seen in part (c), adding ethanol and ethanoic acid to a reaction vessel. They set the reaction up in a closed system, at a constant temperature and allowed equilibrium to be reached. 

The reaction was done in a container with a volume of 250 cm³. 

Table below shows the amount of each substance present in the equilibrium mixture. 

i) Calculate K_c for this reaction to 2 decimal places.

ii) Deduce the units for K_c.