You are given solutions of HCl and NaOH and must determine their concentrations. You use 38 mL of NaOH to titrate 100 mL of HCl and 23.2 mL of NaOH to titrate 50 mL of 0.0782 M H2SO4. Find the unknown concentrations.

Answer 1

I think you made a typo in the question. You were given unknown solns of HCl and H2SO4?
HCl + NaOH ==> NaCl + H2O
moles NaOH = M x L
moles HCl = same (since equation shows 1:1).
M HCl = moles/L

H2SO4 + 2NaOH ==> Na2SO4 + 2H2O
moles NaOH = M x L
moles H2SO4 = 1/2 moles NaOH (look at the equation).
M H2SO4 = moles/L