Stoichiometry Calculator
Goes from a known amount of one substance to the amount of another in the same balanced equation.
Mass of the substance you want
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Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
Moles of the substance you want — mol
Moles of the known substance — mol
Mole ratio, wanted to known —
Reading this —
The formula
moles wanted = moles known × (coefficient wanted ÷ coefficient known) mass = moles × molar mass
The coefficients of a balanced equation give the ratio of moles, not of masses.
What to watch out for
The default values are the thermal decomposition of calcium carbonate: CaCO₃ → CaO + CO₂.
Frequently Asked Questions
How much carbon dioxide comes from 10 g of calcium carbonate?
4.397 g, since one mole of CaCO₃ gives one mole of CO₂.
Why can I not use the mass ratio directly?
A balanced equation counts particles, and different substances have different particle masses. Masses have to go through moles.