25cm^3 H2SO4 is neutralized by 40 cm^3 of 0.03 mol/dm^3 KOH. What is the molar concentration of H2SO4?

Answer 1

H2SO4 + 2KOH ==> K2SO4 + 2H2O

mols KOH = M x L = ?
Using the coefficients in the balanced equation, convert mols KOH to mols H2SO4.
Then M H2SO4 = mols H2SO4/L H2SO4.

Answer 2

40cm^3 * (1dm/10cm)^3 * .03mol/dm^3 = 0.0012 mol KOH

Each mole of H2SO4 needs 2 moles of KOH to be neutralized.

That means you had .0006 mol H2SO4

.0006mol/25cm^3 * 1000cm^3/L = 0.24mol/L = 0.24M H2SO4