How much mass would a mole of hydrogen molecules contain?
recall that hydrogen is diatomic.
g/mol.

2.016 g/mol

Explanation:

Avogadro number

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

For H₂:

2.016 g of H₂ = one mole of hydrogen gas = 6.022 × 10²³ molecules of hydrogen

it should be p1 v1 = p2 v2