Question

Given the reaction: 2Al + 3H2SO4 → 3H2 + Al2(SO4)3 The total number of moles of H2SO4 needed to react completely with 5.0 moles of Al is

Answer 1

Answer : The number of moles of $H_2SO_4$ needed, 7.5 mole

Solution : Given,

Moles of Al = 5.0 moles

The balanced chemical reaction is,

$2Al+3H_2SO_4\rightarrow 3H_2+Al_2(SO_4)_3$

From the balanced chemical reaction, we conclude that

As, 2 moles of Al react with 3 moles of $H_2SO_4$

So, 5.0 moles of Al react with $\frac{3}{2}\times 5.0=7.5$ moles of $H_2SO_4$

Therefore, the number of moles of $H_2SO_4$ needed, 7.5 mole

Answer 2

2 mol Al - 3 mol H₂SO₄

5 mol Al - x mol H₂SO₄

x=5*3/2=7.5

n(H₂SO₄)=7.5 mol