Molar Mass of KOH (Potassium Hydroxide)

Molar Mass Calculator

What is the molar mass of KOH?

Answer

M(KOH) =

56.105 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
Kpotassium	1	39.098	39.098 w ≈ 69.69%	≈ 69.69%
Ooxygen	1	15.999	15.999 w ≈ 28.52%	≈ 28.52%
Hhydrogen	1	1.0080	1.0080 w ≈ 1.80%	≈ 1.80%
Σ = 56.105 g/mol w = 100%				100%

Each fraction is rounded on its own, so the printed ones add up to 100.01%; unrounded, they make exactly 100%.

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

Mass fractions of the elements

K 69.69%

O 28.52%H 1.80%

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Molar masses of substances nearby

Formula	M, g/mol
Mn (manganese)	54.938
Fe (iron)	55.845
CaO (calcium oxide)	56.077
KOH (potassium hydroxide)	56.105
C₄H₈ (isobutylene)	56.108
MgS (magnesium sulfide)	56.37
C₃H₆O (acetone)	58.080

FAQ

What is the molar mass of KOH?

M(KOH) = 56.105 g/mol

How to calculate the molar mass of KOH?

Add up the atomic weights of all the atoms in the formula: 39.098 + 15.999 + 1.0080 = 56.105 g/mol.

How many grams are in 2 moles of KOH?

m = n × M = 2 mol × 56.105 g/mol = 112.210 g.

See Also