Molar Mass of CH2O (Formaldehyde)

Molar Mass Calculator

What is the molar mass of CH₂O?

Answer

M(CH₂O) =

30.026 g/mol

Atomic weights: IUPAC standard values (CIAAW, 2024).

Contribution of each element
Element	Atoms, n	Atomic weight, A	n × A, g/mol Mass fraction, w	Mass fraction, w
Ccarbon	1	12.011	12.011 w ≈ 40.00%	≈ 40.00%
Hhydrogen	2	1.0080	2.0160 w ≈ 6.71%	≈ 6.71%
Ooxygen	1	15.999	15.999 w ≈ 53.28%	≈ 53.28%
Σ = 30.026 g/mol w = 100%				100%

Each fraction is rounded on its own, so the printed ones add up to 99.99%; unrounded, they make exactly 100%.

Atomic weights: CIAAW, Abridged Standard Atomic Weights (2024)

Mass fractions of the elements

O 53.28%C 40.00%

H 6.71%

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Molar masses of substances nearby

Formula	M, g/mol
Si (silicon)	28.085
Li₂O (lithium oxide)	29.88
NO (nitric oxide)	30.006
CH₂O (formaldehyde)	30.026
C₂H₆ (ethane)	30.070
P (phosphorus)	30.974
CH₅N (methylamine)	31.058

FAQ

What is the molar mass of CH2O?

M(CH₂O) = 30.026 g/mol

How to calculate the molar mass of CH₂O?

Add up the atomic weights of all the atoms in the formula: 12.011 + 2 × 1.0080 + 15.999 = 30.026 g/mol.

How many grams are in 2 moles of CH₂O?

m = n × M = 2 mol × 30.026 g/mol = 60.052 g.

See Also