Molar Mass of H₂

Hydrogen gas (dihydrogen). The lightest gas; hydrogen gas is diatomic H₂.

Molar mass of H2
2.016 g/mol
2 × 1.008 = 2.016

Calculation, element by element

ElementAtomsAtomic mass (g/mol)SubtotalMass %
Hydrogen (H)21.0082.016100.00%
Total2.016100%

= 4.9603 mol = 2.9872 × 1024 molecules

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H₂ molar mass FAQ

What is the molar mass of hydrogen gas (H₂)?

2.016 g/mol. It is the sum of the atomic masses of every atom in the formula: 2 × 1.008 = 2.016 g/mol.

How many grams are in one mole of H₂?

2.016 g. Molar mass is the mass of one mole (6.022 × 10²³ formula units), so 1 mol of H₂ weighs 2.016 g and 0.5 mol weighs 1.008 g.

How many moles are in 10 g of H₂?

10 g ÷ 2.016 g/mol = 4.960 mol.

What is the percent composition of H₂?

Hydrogen 100.00%.

Is molecular weight the same as molar mass for H₂?

Numerically yes: the molecular (or formula) weight is 2.016 u per formula unit, and the molar mass is 2.016 g/mol.

Molar masses of other common compounds