How much magnesium can react with a solution containing 19.6 g of sulfuric acid?

Let’s write the reaction equation:
Mg + H2SO4 = MgSo4 + H2O
It can be seen from the reaction equation that:
ν (H2SO4) = ν (Mg)
m (H2SO4) / M (H2SO4) = m (Mg) / M (Mg)
Let’s define the molar masses:
M (H2SO4) 1 * 2 + 32 + 16 * 4 = 98 g / mol
M (Mg) = 24 g / mol
Determine the mass of magnesium:
m (Mg) = m (H2SO4) * M (Mg) / M (H2SO4) = 19.6 * 24/98 = 4.8 g.
Answer: the mass of magnesium is 4.8 g.