A 0.2512 stock sample of HCl is tirade to equivalence . If 16.77ml of 0.1410 M NaOH is required to reach the equivalence point, what volume of stock HCl was used for the tritation?

Answer 1

Is that 0.2512 M stock? I will assume it is.
mols NaOH = M x L = ?
mols HCl = mols NaOH (since 1 mol HCl = 1 mol NaOH in the balanced equation).
M HCL stock = mols/L.
You know M and you know mols, solve for L and change to mL if desired.

Answer 2

yes 0.2512 M stock so,
0.1410m x 0.01677L= 2.36457^-03 mole used.
mols HCL = mols NaOH 0.2512M=2.36457^3

Answer 3

What am I missing ?
Should there be another step?