Calculate the change in $pH$ achieved by adding $2.000\; mmol$ $NaOH$ to
a) $1\; L$ of a buffer of $0.0200M$ propionic acid and $0.0150\;M$ sodium propanoate .
$\Delta pH$ $ = $ $0.10 $
b) $1000\; mL$ water (neglecting the variation of volume).
$\Delta pH$ $ = $ $4.30 $
