Molar MassMolar mass of sodium chloride (NaCl)
The molar mass of sodium chloride, NaCl, is 58.44 g/mol. One mole of it, which is 6.022 × 1023 formula units, has a mass of 58.44 grams.
58.44 g/mol
22.990 + 35.45 = 58.440 · 2 atoms in the formula · also called common salt, table salt
About sodium chloride
Sodium chloride is common salt. It is an ionic solid made of sodium ions and chloride ions in equal numbers, with no separate molecules. It is the usual first example for mole calculations because its formula could not be simpler.
Other names: common salt, table salt.
The working
The formula NaCl has 1 sodium atom and 1 chlorine atom, 2 atoms in all. Multiply each count by the atomic weight of the element and add:
| Element | Atoms | Atomic weight | Total | Share by mass |
|---|---|---|---|---|
| Sodium (Na) | 1 | 22.990 | 22.990 | 39.34% |
| Chlorine (Cl) | 1 | 35.45 | 35.450 | 60.66% |
22.990 + 35.45 = 58.440 g/mol
With the rounded atomic masses used in many school books (Na = 23, Cl = 35.5) the answer is 58.5 g/mol. The difference from 58.44 is too small to matter in most school sums.
Percentage composition
By mass, NaCl is 39.34% sodium and 60.66% chlorine. The largest share comes from chlorine. In a 100 g sample there are 39.3 g of sodium and 60.7 g of chlorine.
Worked examples
Grams to moles. How many moles are in 100 g of NaCl? Divide the mass by the molar mass: 100 ÷ 58.44 = 1.711 mol.
Moles to grams. What is the mass of 2 mol of NaCl? Multiply: 2 × 58.44 = 116.9 g.
Counting particles. 100 g contains 1.711 mol × 6.022 × 1023 = 1.030 × 1024 formula units.
Making a solution. A 0.1 mol/L solution contains 0.1 × 58.44 = 5.844 g of NaCl in each litre. For 250 mL, weigh 1.461 g and make it up to the mark with water.
Quick conversion tables
| Amount | Mass |
|---|---|
| 0.1 mol | 5.844 g |
| 0.5 mol | 29.22 g |
| 1 mol | 58.44 g |
| 2 mol | 116.9 g |
| 5 mol | 292.2 g |
| Mass | Moles |
|---|---|
| 1 g | 0.01711 mol |
| 10 g | 0.1711 mol |
| 100 g | 1.711 mol |
| 1 kg | 17.11 mol |
For other amounts use the grams and moles converter.
Questions people ask
What is the molar mass of NaCl?
The molar mass of sodium chloride (NaCl) is 58.44 g/mol, or 58.440 g/mol before rounding, using IUPAC abridged atomic weights.
How many moles are in 100 g of NaCl?
100 ÷ 58.44 = 1.711 mol.
What is the mass of one formula unit of NaCl?
Divide the molar mass by the Avogadro constant: 58.44 ÷ 6.022 × 1023 = 9.704 × 10-23 g.
What is the percentage of chlorine in NaCl?
Chlorine makes up 60.66% of the mass of NaCl: 1 × 35.45 ÷ 58.440 × 100.
Which values? This site uses the abridged standard atomic weights published by IUPAC (CIAAW), read on 12 November 2026. Your textbook or question paper may round them differently, for example H = 1 and O = 16, so its answer can differ slightly. In an exam, use the values the paper gives.