# A buffer solution is formed when 10.0 cm^3 of 0.230 mol dm^-3 aqueous sodium hydroxide are added to 30.0 cm^3 of 0.550 mol dm^-3 aqueous propanoic acid. How do you calculate the number of moles of propanoic acid originally present?

May 7, 2018

I will assume you don't need this solved, but want a starting point since that is what you're asking.

To calculate the moles of propanoic acid, we do a simple stoichiometric calculation,

$0.030 \text{mL" * (0.550"mol")/"L" approx 1.65*10^-2"mol}$

The same goes for the initial hydroxide added.