When microbes are grown in the laboratory, buffered media are employed to ensure that pH does not change during the reaction. Buffer solutions are aqueous solutions consisting of a mixture of a weak acid and its conjugate base. Their pH changes very little when a strong acid or a strong base is added to it. (a) Based on the reaction table below, show that xeq10.01KAmolL1, where KAA is the reaction constant for the dissociation of acetic acid (CH3COOH). What approximation do you have to make? [3] (b) The pKA for the dissociation of acetic acid (CH3COO)is 4.75 . What is the pH at equilibrium for this reaction? (c) Now let's consider that acetate (CH3COO)was also added at the beginning of the reaction with a concentration equal to 0.008M (Table 2). i) Show that xeq20.0080.01KA. You will need to make the assumption as above. [2] ii) What would the pH at equilibrium be in this case? [1] (d) If after equilibrium was reach, a strong acid equivalent to 0.004M of [H3O+]was added to the aqueous solution in the second table, i) How would the equilibrium shift? Use LeChatelier's principle to explain your answer. [3] ii) Considering that the reaction is reactant favoured (or endergonic), what would be a good approximation of how much [H3O+]would be consumed in this case to form CH3COOH ? [3]