Calculate the mass of potassium hydroxide required to neutralize 98 g of sulfuric acid solution with a mass fraction of 30%.

Given:
m (H2SO4) = 98 g
w% (H2SO4) = 30%
To find:
m (KOH) -?
Decision:
2KOH + H2SO4 = K2SO4 + 2H2O, – we solve the problem, relying on the composed reaction equation:
1) Find the mass of acid in the solution that has reacted:
m (H2SO4) = 98 g * 0.3 = 29.4 g
2) Find the amount of acid:
n (H2SO4) = m: M = 29.4 g: 98 g / mol = 0.3 mol
3) We compose a logical expression:
If 2 mol KOH requires 1 mol H2SO4,
then x mol KOH requires 0.3 mol H2SO4,
then x = 0.6 mol.
4) Find the mass of potassium hydroxide required for the reaction to proceed:
m (KOH) = n * M = 0.6 mol * 56 g / mol = 33.6 g.
Answer: m (KOH) = 33.6 g.