Answer:
Molarity acetate: 0.1353M
Molarity acetic acid: 0.0418M
Explanation:
When in solution you have a weak acid (Acetic acid) and its conjugate base (sodium acetate) a buffer is produced. The pH of this buffer is obtained using the H-H equation:
pH = pKa + log [A⁻] / [HA]
Where pH is pH of the solution = 5.25
pKa is pKa of acetic buffer = 4.74
[A⁻] is molarity of acetate ion - Molar mass sodium acetate: 82.03g/mol-:
11.1g * (1mol / 82.03g) = 0.1353moles A⁻ / 1.0L = 0.1353M
And [HA] are moles of acetic acid.
Solving for HA:
5.25 = 4.74 + log [0.1353] / [HA]
0.51 = log [0.1353] / [HA]
3.236 = [0.1353] / [HA]
[HA] = 0.1353M / 3.236
[HA] = 0.0418M
