Question

When ethyl alcohol and acetic acid mixed together in equimolecular proportions, equilibrium is attained when two-third of the acid and alcohol are consumed. the equilibrium constant for the reaction will be?

Answer 1

According to the definition, "Equilibrium constant (Kc) is the ratio of the products of the product concentration that is raised to the powers of their coefficient to the products of the reactant concentration that is raised to powers of their coefficient."

The reaction equation will be - 

C₂H₅OH + CH₃COOH → CH₃COOC₂H₅ + H₂O

In this equation, the coefficients are all 1 and so, the exponents are disregarded. Also, in this esterification reaction, 1 mole of water is produced for every mole of ethyl acetate produced.

Kc = frac of {[H₂O] x [CH₃COOC₂H₅]} {[CH₃COOH] x [C₂H₅OH]}

Kc = ((2/3) x (2/3)/1 = (4/9)

Therefore, Kc = 0.44.

Answer 2

C2H5OH +CH3COOH =CH3COOC2H5 +H2O

Concentration before equillibrium:

C2H5OH=C

CH3COOH=C

CH3COOC2H6=H2O=0

Concentration after equilibrium :

C2H5OH=CH3COOH=C-(2/(3*C))

CH3COOC2H5=H2O=(2/(3*C))

K=((2/(3*C))^2) / ((C-(2/(3*C)))^2)

K=4