Molar Mass of Potassium hydroxide

KOH — 56.105 g/mol, worked out element by element.

Molar mass of Potassium hydroxide, KOH

56.105 g/mol

Molecular weight 56.105 · 3 atoms per formula unit

Also known as: koh, caustic potash.

Sodium hydroxide's heavier twin, preferred in soft soaps and alkaline batteries.

How 56.105 g/mol is worked out

Mass contribution of each element
ElementAtomsAtomic massMass% of total
Potassium139.09839.09869.69%
Oxygen115.99915.99928.52%
Hydrogen11.0081.0081.80%
Total356.105100%

M = 1 × 39.098 + 1 × 15.999 + 1 × 1.008 = 56.105 g/mol

Grams to moles for Potassium hydroxide

Mass to moles conversions
MassMolesFormula units
1 g0.0178 mol1.073 × 10^22
10 g0.1782 mol1.073 × 10^23
25 g0.4456 mol2.683 × 10^23
50 g0.8912 mol5.367 × 10^23
100 g1.7824 mol1.073 × 10^24
250 g4.4559 mol2.683 × 10^24
56.105 g1 mol6.022 × 10^23

For any other amount, use the molar mass calculator, or the molarity calculator to make up a solution of a given concentration.

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Frequently Asked Questions

What is the molar mass of Potassium hydroxide?

The molar mass of Potassium hydroxide (KOH) is 56.105 g/mol. That is the sum of the standard atomic weights of all 3 atoms in one formula unit: 1 × 39.098 + 1 × 15.999 + 1 × 1.008 = 56.105.

What is the molecular weight of Potassium hydroxide?

56.105 — the same number as the molar mass, but as a dimensionless ratio rather than in g/mol. The two terms describe the same arithmetic, so a molecular weight of 56.11 and a molar mass of 56.11 g/mol are the same answer.

How many moles are in 100 g of Potassium hydroxide?

100 ÷ 56.105 = 1.7824 mol. To convert any mass to moles, divide by the molar mass; to go the other way, multiply.

What is the percent composition of Potassium hydroxide?

By mass, Potassium hydroxide is 69.69% potassium, 28.52% oxygen, 1.80% hydrogen. Each element's share is its total mass in the formula divided by 56.105.

How many atoms are in one formula unit of Potassium hydroxide?

3: 1 potassium, 1 oxygen, 1 hydrogen. One mole contains 6.02214076 × 10²³ formula units, so a mole of Potassium hydroxide contains 3 × 6.022 × 10²³ atoms in total.