Molar Mass of CaCO₃

Calcium carbonate (limestone, chalk). Made of Ca²⁺ and CO₃²⁻ ions. It is the main component of limestone, marble and eggshells.

Molar mass of CaCO3
100.086 g/mol
1 × 40.078 + 1 × 12.011 + 3 × 15.999 = 100.086

Calculation, element by element

ElementAtomsAtomic mass (g/mol)SubtotalMass %
Calcium (Ca)140.07840.07840.04%
Carbon (C)112.01112.01112.00%
Oxygen (O)315.99947.99747.96%
Total100.086100%

= 0.099914 mol = 6.017 × 1022 formula units

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CaCO₃ molar mass FAQ

What is the molar mass of calcium carbonate (CaCO₃)?

100.086 g/mol. It is the sum of the atomic masses of every atom in the formula: 1 × 40.078 + 1 × 12.011 + 3 × 15.999 = 100.086 g/mol.

How many grams are in one mole of CaCO₃?

100.086 g. Molar mass is the mass of one mole (6.022 × 10²³ formula units), so 1 mol of CaCO₃ weighs 100.086 g and 0.5 mol weighs 50.043 g.

How many moles are in 10 g of CaCO₃?

10 g ÷ 100.086 g/mol = 0.09991 mol.

What is the percent composition of CaCO₃?

Calcium 40.04%, Carbon 12.00%, Oxygen 47.96%.

Is molecular weight the same as molar mass for CaCO₃?

Numerically yes: the molecular (or formula) weight is 100.086 u per formula unit, and the molar mass is 100.086 g/mol.

Molar masses of other common compounds