What is the pH of a 0.05 M solution of sodium ethanoate ?
#sf(pK_a)# value for ethanoic acid is 4.66.
Sodium ethanoate is the salt of a weak acid and strong base so undergoes hydrolysis:
Note that these refer to equilibrium concentrations.
We can find the
Because the equilibrium is well to the left we can assume that the equilibrium concentration of
By rearranging the expression for
Putting in the numbers: