Atomic Mass of Nitrogen
| Value | 0.014007 kg/mol |
| Status | Measured: ± 0.000001 kg/mol (0.000071 relative) |
| Source | IUPAC |
| Categories | Chemistry |
| gram per mole | 14.007 g/mol |
| kilogram per kilomole | 14.007 kg/kmol |
| milligram per millimole | 14.007 mg/mmol |
| pound per pound-mole | 14.007 lb/lb-mol |
| dalton (as molar mass) | 14.007 Da |
| kilogram per mole | 0.014007 kg/mol |
| kilodalton (as molar mass) | 0.014007 kDa |
Learning zone
Nitrogen's 14.007 g/mol is nearly all ¹⁴N, with just 0.36 % ¹⁵N, so the standard atomic weight sits very close to a whole number. It is the number that converts between a compound and its nitrogen content: urea, CH₄N₂O at 60.06 g/mol, carries 2 × 14.007 = 28.014 g of nitrogen per mole, which is 46.6 % N — the figure printed as the first number of a fertiliser's N-P-K grade.
The same division runs through environmental reporting, where ammonia, nitrate and nitrite are all normalised "as N" so that they can be added into a single total nitrogen figure. Nitrate at 62.00 g/mol is 22.6 % nitrogen, so the drinking-water limit of 10 mg/L as N is 44.3 mg/L as NO₃⁻ — the same water, two numbers, and a standard source of confusion between American and European reporting conventions.