Question

15.00 ml of NaOH is obtained in an Erlenmeyer flask. Before titrating with .2500 M HCl, the initial volume of acid in a buret is read as 2.08 ml. At the endpoint the final volume of acid in the buret is 25.20 ml. What was the concentration of NaOH?

Answer 1

mols HCl = M x L.
M you have as 0.2500.
L. Final 25.20mL - 2.08 mL = mL HCl. Convert to L and find mols as above.
Then mols NaOH = mols HCl.
M NaOH = mols NaOH/L NaOH. Solve for M.