Assume that 35.0 mL of a 0.13 M solution of a weak base B that accepts one proton is titrated with a 0.13 M solution of the monoprotic strong acid HX.

Question

(a) How many moles of HX have been added at the equivalence point?

Answer 1

How many mols did you start with? That's M x L = 0.13 x 0.035 = ?
That's how many mols HX you have at the equivalence point. You didn't ask but it will take 35.0 mL of the acid to titrate the base.