Question

8) Predict the mass of hydrogen gas produced when 2.73 g of aluminum reacts in a single replacement reaction with excess sulphuric acid.

2Al + 3H2SO4 -> 3H2 + Al2(SO4)3

Answer 1

Molecular weight of Al = 26.98

Molecular weight of H2 = 2.01

$2Al + 3H_2SO_4-->3H_2+Al_2(SO4)_3$

Moles of $Al= \frac{2.73}{26.98}=0.101$

Moles of $H_2 =\frac {3×0.101}{2}=0.1515moles$

Mass of $H_2 = 0.1515×2.01= 0.3045grams$