posted by blair .
72.33 mL of 0.137 M HCl was added to an Erlenmeyer flask and is titrated with 0.165 M NaOH. Calculate the pH when 5mL of NaOH is added after the equivalence point has been reached.
First determine L NaOH for the equivalence point.
mols excess NaOH = M NaOH x L NaOH.
New M NaOH = mols excess/total volume.
(Note: total volume = volume to reach the equivalence point + 5 mL)
That will give you the M of OH^-, then pOH = -log(OH^-) followed by
pH + pOH = pKw = 14. Solve for pH.
how do you determine the L NaOH?
MHCl x L HCl = M NaOH x L NaOH
mols HCl= molsNaOH?