Molar Mass of Oxalic acid

H2C2O4 — 90.034 g/mol, worked out element by element.

Molar mass of Oxalic acid, H₂C₂O₄

90.034 g/mol

Molecular weight 90.034 · 8 atoms per formula unit

Also known as: h2c2o4, ethanedioic acid.

A diprotic acid used to standardise permanganate solutions, and the reason rhubarb leaves are toxic.

How 90.034 g/mol is worked out

Mass contribution of each element
ElementAtomsAtomic massMass% of total
Oxygen415.99963.99671.08%
Carbon212.01124.02226.68%
Hydrogen21.0082.0162.24%
Total890.034100%

M = 4 × 15.999 + 2 × 12.011 + 2 × 1.008 = 90.034 g/mol

Grams to moles for Oxalic acid

Mass to moles conversions
MassMolesFormula units
1 g0.0111 mol6.689 × 10^21
10 g0.1111 mol6.689 × 10^22
25 g0.2777 mol1.672 × 10^23
50 g0.5553 mol3.344 × 10^23
100 g1.1107 mol6.689 × 10^23
250 g2.7767 mol1.672 × 10^24
90.034 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 Oxalic acid?

The molar mass of Oxalic acid (H2C2O4) is 90.034 g/mol. That is the sum of the standard atomic weights of all 8 atoms in one formula unit: 4 × 15.999 + 2 × 12.011 + 2 × 1.008 = 90.034.

What is the molecular weight of Oxalic acid?

90.034 — 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 90.03 and a molar mass of 90.03 g/mol are the same answer.

How many moles are in 100 g of Oxalic acid?

100 ÷ 90.034 = 1.1107 mol. To convert any mass to moles, divide by the molar mass; to go the other way, multiply.

What is the percent composition of Oxalic acid?

By mass, Oxalic acid is 71.08% oxygen, 26.68% carbon, 2.24% hydrogen. Each element's share is its total mass in the formula divided by 90.034.

How many atoms are in one formula unit of Oxalic acid?

8: 4 oxygen, 2 carbon, 2 hydrogen. One mole contains 6.02214076 × 10²³ formula units, so a mole of Oxalic acid contains 8 × 6.022 × 10²³ atoms in total.