Calculate the mass of KOH that can react with 250 g of H2SO4.

Given:
m (H2SO4) = 250 g
KOH reacts with H2SO4
Find: m (KOH) -?
Solution:
1) Let’s compose the reaction equation:
2KOH + H2SO4 = K2SO4 + 2H2O
2) Find the amount of substance (v) for H2SO4
v = m / M
M (H2SO4) = 1 * 2 + 32 + 16 * 4 = 34 + 64 = 98 g / mol
v (H2SO4) = 250/98 = 2.55 mol
3) Let’s make the proportion in relation to the amount of substance (v):
v (KOH) / 2 mol = 2.55 mol / 1 mol
v (KOH) = 2.55 * 2 = 5.1 mol
4) m (KOH) = v (KOH) * M (KOH)
M (KOH) = 40 + 1 + 16 = 57 g / mol
m (KOH) = 5.1 * 57 = 290.7 g
Answer: m (KOH) = 290.7 g.