Calculate the pOH after addition of 6.920 mL of 0.1779 M HBr to 25.00 mL of 0.1155 M C5H11N. Kb(C5H11N) = 1.300e-3.
Key Concept: Titration of a weak base by a strong acid. Up to just before the equivalence point, the Henderson-Hasselbach equation can be used to determine pH. Although this is not the normal form it works quite nicely: pH = pKa − log(nb/na)
Strategy Calculate initial mol of base, calculate mole of acid added → nb = initial mol of base minus mol acid added; na = mol of acid added.;