find volume of 0.2 M sulfuric acid required to react with 15.0 ml of 0.25 M sodium hydroxide
H2SO4 + 2NaOH ==> Na2SO4 + 2H2O
mols NaOH = mols x L = ?
Use the coefficients in the balanced equation to convert mols NaOH to mols H2SO4.
Then M H2SO4 = mols H2SO4/L H2SO4. You know M and mols, solv eof L; convert to mL if desired.