# How many milimoles of acetate need to be added to create a buffer of pH = 5.05 in the following case. You have a solution that contains 10 mmol of acetic acid. How many millimoles of acetate do you need to add to this solution? The pKa of acetic acid is 4.74. The pH of a buffer solution is given by:

pH = pKa + log [(A-)/(HA)], where (A-) is the concentration of the conjugate base and (HA) is the concentration of the acid.And pKa is the acid dissociation constant which is given as 4.74.

We have to produce a buffer solution with a pH of 5.05. The acid solution given has 10 mmol of acetic acid. So, we have (HA) = 10 mmol. The required number of milimoles of acetate to be added to this solution can be found using the equation:

5.05 = 4.74 + log(10) [ (A-)/ 10]

=> 5.05 - 4.74 = log(10) [(A-)/10]

=> 0.31 = log(10) [ (A-)/10]

=> [(A-)/ 10] = 10^0.31

=> (A-) = 10*10^0.31

=> (A-) = 10^1.31

=> (A-) = 20.417

The number of milimoles of acetate to be added is 20.417.

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