Molar Mass of Magnesium oxide

MgO — 40.304 g/mol, worked out element by element.

Molar mass of Magnesium oxide, MgO

40.304 g/mol

Molecular weight 40.304 · 2 atoms per formula unit

Also known as: mgo, magnesia.

The white ash from burning magnesium ribbon, and a refractory that survives 2,800 °C.

How 40.304 g/mol is worked out

Mass contribution of each element
ElementAtomsAtomic massMass% of total
Magnesium124.30524.30560.30%
Oxygen115.99915.99939.70%
Total240.304100%

M = 1 × 24.305 + 1 × 15.999 = 40.304 g/mol

Grams to moles for Magnesium oxide

Mass to moles conversions
MassMolesFormula units
1 g0.0248 mol1.494 × 10^22
10 g0.2481 mol1.494 × 10^23
25 g0.6203 mol3.735 × 10^23
50 g1.2406 mol7.471 × 10^23
100 g2.4811 mol1.494 × 10^24
250 g6.2029 mol3.735 × 10^24
40.304 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 Magnesium oxide?

The molar mass of Magnesium oxide (MgO) is 40.304 g/mol. That is the sum of the standard atomic weights of all 2 atoms in one formula unit: 1 × 24.305 + 1 × 15.999 = 40.304.

What is the molecular weight of Magnesium oxide?

40.304 — 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 40.30 and a molar mass of 40.30 g/mol are the same answer.

How many moles are in 100 g of Magnesium oxide?

100 ÷ 40.304 = 2.4811 mol. To convert any mass to moles, divide by the molar mass; to go the other way, multiply.

What is the percent composition of Magnesium oxide?

By mass, Magnesium oxide is 60.30% magnesium, 39.70% oxygen. Each element's share is its total mass in the formula divided by 40.304.

How many atoms are in one formula unit of Magnesium oxide?

2: 1 magnesium, 1 oxygen. One mole contains 6.02214076 × 10²³ formula units, so a mole of Magnesium oxide contains 2 × 6.022 × 10²³ atoms in total.