Stoichiometry & gases · SL/HL

Moles, mass & particles

Convert between mass, moles and particle count.

Your values

Number formats & units

Use decimal dots in datasets. Single values also accept decimal commas and scientific notation such as 1.2e-3 or 1.2 × 10⁻³.

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Example

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n=\frac mM

m=nM

N=nN_{\mathrm A}

N_{\mathrm A}=6.02214076\times10^{23}\,\mathrm{mol}^{-1}

What the variables mean

Symbol	Meaning
$n$	Amount of substance in mol.
$m$	Mass in g when M is in g mol⁻¹.
$M$	Molar mass in g mol⁻¹.
$N$	Number of specified particles.

0.1001027 mol

Follow the example steps

Divide mass by molar mass to find amount.

m = 10 g, M = 20 g mol⁻¹: n = 10 × 20 = 200 mol

n = 10/20 = 0.5 mol

More checks before you submit

Do not multiply by molar mass when you need moles; divide mass by molar mass.
A chemical formula determines molar mass; this tool does not infer the formula from a name.

Method notes

Use stoichiometric coefficients on amounts in moles, not directly on masses. State what the “particles” are: atoms, molecules, ions or formula units.