Question

1 g of hydrogen contains how many atoms of hydrogen?

Options

• 3.011 × 10²³

• 2.5 × 10²³

• 6.022 × 10²³

• None of these

Answer 1

6.022 × 10²³

Explanation:

Hydrogen exists as H₂, so its molar mass = 2 g/mol

1 g of H₂ = `1/2`​ mol

Number of H₂ molecules:

`1/2 xx 6.022 xx 10^23`

= 3.011 × 10²³

Each H₂ molecule contains 2 hydrogen atoms, so:

3.011 × 10²³ × 2

= 6.022 × 10²³ atoms​