Molar Mass of Sodium thiosulfate

Na2S2O3 — 158.097 g/mol, worked out element by element.

Molar mass of Sodium thiosulfate, Na₂S₂O₃

158.097 g/mol

Molecular weight 158.097 · 7 atoms per formula unit

Also known as: na2s2o3, hypo, sodium thiosulphate.

Photographic fixer, and the titrant for iodine in iodometry.

How 158.097 g/mol is worked out

Mass contribution of each element
ElementAtomsAtomic massMass% of total
Sulfur232.0664.12040.56%
Oxygen315.99947.99730.36%
Sodium222.9945.98029.08%
Total7158.097100%

M = 2 × 32.060 + 3 × 15.999 + 2 × 22.990 = 158.097 g/mol

Grams to moles for Sodium thiosulfate

Mass to moles conversions
MassMolesFormula units
1 g0.0063 mol3.809 × 10^21
10 g0.0633 mol3.809 × 10^22
25 g0.1581 mol9.523 × 10^22
50 g0.3163 mol1.905 × 10^23
100 g0.6325 mol3.809 × 10^23
250 g1.5813 mol9.523 × 10^23
158.097 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 Sodium thiosulfate?

The molar mass of Sodium thiosulfate (Na2S2O3) is 158.097 g/mol. That is the sum of the standard atomic weights of all 7 atoms in one formula unit: 2 × 32.060 + 3 × 15.999 + 2 × 22.990 = 158.097.

What is the molecular weight of Sodium thiosulfate?

158.097 — 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 158.10 and a molar mass of 158.10 g/mol are the same answer.

How many moles are in 100 g of Sodium thiosulfate?

100 ÷ 158.097 = 0.6325 mol. To convert any mass to moles, divide by the molar mass; to go the other way, multiply.

What is the percent composition of Sodium thiosulfate?

By mass, Sodium thiosulfate is 40.56% sulfur, 30.36% oxygen, 29.08% sodium. Each element's share is its total mass in the formula divided by 158.097.

How many atoms are in one formula unit of Sodium thiosulfate?

7: 2 sulfur, 3 oxygen, 2 sodium. One mole contains 6.02214076 × 10²³ formula units, so a mole of Sodium thiosulfate contains 7 × 6.022 × 10²³ atoms in total.