When zinc reacts with sulfuric acid, as shown here, what mass of hydrogen is produced from 31.8 g of zinc?
Zn + H2SO4 ⇒ ZnSO4 + H2

The answer to your question is 0.98 g of H₂

Explanation:

Data

mass of H₂ = ?

mass of Zn = 31.8 g

Balanced chemical reaction

                Zn  +  H₂SO₄  ⇒   ZnSO₄  +  H₂

Process

1.- Calculate the molar mass or atomic mass of Zinc and hydrogen

The Atomic mass of zinc = 65 g

The Molar mass of H₂ = 2 g

2.- Use proportions and cross multiplication to find the mass of H₂ formed.

                       65 g of Zn 2 g of H₂

                        31.8 g of Zn  x

                            x = (31.8 x 2) / 65

                            x = 63.6/65

-Result

                            x = 0.98 g of H₂