An unknown amount of water is mixed with 310 mL of a 6 M solution of NaOH solution. A 75 mL sample of the resulting solution is titrated to neutrality with 58.2 mL of 6 M HCl. Calculate the concentration of the diluted NaOH solution. Answer in units of M

Question

What volume of water was added to the 310 mL of NaOH solution? Assume volumes are additive. Answer in units of mL

Answer 1

M of the 75 mL =
58.2 mL x 6M/75 mL = 4.656M

So the initial solution must have been
6M NaOH x 310 mL = 4.656M x ? mL
Solve for ? mL, then subract 310 from it to see how much water was added.