Question

What mass of NaOH(s) must be added to 300 mL of HCl 0.25 M in order to completely neutralize this acid?

Answer 1

How many mols HCl do you have? M x L = mols.
Write the equation. How many mols NaOH do you need?
mols NaOH = grams/molar mass. Solve for grams.