What volume of 0.500 M hydrochloric acid is required to exactly neutralize 40.00 mL 0.150 M NaOH?

Answer 1

How many moles NaOH do you have. That is M x L = ?
The equation is HCl + NaOH ==> NaCl + H2O
From the equation, it is obvious that moles HCl = moles NaOH.
Then M HCl = moles HCl/L HCl
Solve for volume HCl.

Answer 2

.003 mL