20.0 ml of 1.00 M formic acid are combined with 10.0 ml of 1.00 M sodium formate. Calculate the expected pH.

Question

Ka for formic acid is 1.77 x 10^-4

Answer 1

Use the Henderson-Hasselbalch equation.
Convert Ka to pKa.
10.0 mL x 1.0 M sodium format is 10 millimols base.
20.0 mL x 1.00 M formic acid is 20 mmols of the acid. Plug and chug.