Mole to Mass Converter

Why it matters

Imagine holding a single carbon atom in your hand. Now imagine holding 6.022 × 10²³ of them — that pile weighs exactly 12 grams.

Predict first

If you have exactly 1 mole of Oxygen atoms (O), what is their mass?

The atomic mass of Oxygen is 16 u. Therefore, the mass of 1 mole of Oxygen atoms is 16 grams. Note: This is for atoms (O), not molecules (O₂).

• 16 grams — correct
• 8 grams
• 32 grams
• 6.022 grams

What you do

Build an oxygen atom: a neutral oxygen-16 atom has 8 protons, 8 neutrons and 8 electrons; its mass number 16 comes from the 8 protons + 8 neutrons. Now scale up — 6.022 × 10²³ such atoms together weigh exactly 16 grams.

Check yourself

What is the mass of 1 mole of Nitrogen gas (N₂)?

Nitrogen gas exists as diatomic molecules (N₂). Atomic mass of N is 14 u, so molecular mass of N₂ is 14 × 2 = 28 u. Thus, 1 mole of N₂ weighs 28 grams.

How many moles are in 36 grams of Water (H₂O)?

Molar mass of H₂O = (2×1) + 16 = 18 g/mol. Moles = Mass / Molar Mass = 36 g / 18 g/mol = 2 moles.

• 14 grams
• 28 grams — correct
• 7 grams
• 1 mole
• 2 moles — correct
• 18 moles
• 36 moles