Chemistry

Problem

A student titrates 50.0 mL of 0.10 M propionic acid (

pK_a = 4.87

) with 0.10 M NaOH. At which of the following added volumes of NaOH will the solution’s pH change the LEAST per additional millilitre of base? a)

2.0\,\text{mL}

50.0\,\text{mL}

25.0\,\text{mL}

37.5\,\text{mL}