ChemWhiz ReferenceSolutions
Solubility Curves: Solubility of Salts vs Temperature
Interactive solubility curves for nine common salts in water (g of solute per 100 g of H2O, 0 to 100 °C). Click or tap anywhere on a curve to read the solubility at that temperature. Points below a curve are unsaturated, on the curve saturated, and above it supersaturated.
01Use this when
Reading how much solute saturates water at a temperature, plus recrystallization and precipitation-on-cooling.
02Conditions
Grams of solute per 100 g water, 0 °C to 100 °C.
03Watch out
Most solids dissolve more when heated, but a few (e.g. Ce2(SO4)3) dissolve less; read the curve.
Solubility vs Temperature (g per 100 g water)
Grams of solute that saturate 100 g of water at each temperature; use the chart to compare salts.
| Ammonium chloride | NH4Cl | 29.4 | 33.2 | 37.2 | 41.4 | 45.8 | 50.4 | 55.3 | 60.2 | 65.6 | 71.2 | 77.3 |
| Potassium bromide | KBr | 53.6 | 59.5 | 65.3 | 70.7 | 75.4 | — | 85.5 | — | 94.9 | 99.2 | 104 |
| Potassium chlorate | KClO3 | 3.3 | 5.2 | 7.3 | 10.1 | 13.9 | — | 23.8 | — | 37.5 | 46 | 56.3 |
| Potassium chloride | KCl | 28 | 31.2 | 34.2 | 37.2 | 40.1 | 42.6 | 45.8 | — | 51.3 | 53.9 | 56.3 |
| Potassium iodide | KI | 128 | 136 | 144 | 153 | 162 | — | 176 | — | 192 | 198 | 206 |
| Potassium nitrate | KNO3 | 13.3 | 20.9 | 31.6 | 45.8 | 63.9 | 85.5 | 110 | 138 | 169 | 202 | 246 |
| Sodium chloride | NaCl | 35.65 | 35.72 | 35.89 | 36.09 | 36.37 | 36.69 | 37.04 | 37.46 | 37.93 | 38.47 | 38.99 |
| Sodium nitrate | NaNO3 | 73 | 80.8 | 87.6 | 94.9 | 102 | — | 122 | — | 148 | — | 180 |
| Sodium sulfate | Na2SO4 | 4.9 | 9.1 | 19.5 | 40.8 | 48.8 | — | 45.3 | — | 43.7 | 42.7 | 42.5 |
Important Notes
- Values are grams of solute that saturate 100 g of water at each temperature. A dash means the compilation has no measurement at that temperature; the curve interpolates between neighbors.
- Most ionic solids dissolve more at higher temperature (steeply for KNO3, barely for NaCl). Sodium sulfate is the classic exception: its solubility peaks between 30 and 40 °C (the Na2SO4·10H2O to Na2SO4 transition at 32.4 °C) and then falls (retrograde solubility).
- Reading the chart: a point below a curve is an unsaturated solution, on the curve saturated, above it supersaturated (crystallization is the usual result of cooling a saturated solution).
- Crossing curves explain fractional crystallization: cooling a hot mixed solution precipitates the salt whose curve falls fastest (e.g. KNO3) while the flat-curve salt (NaCl) stays dissolved.
- This chart and table are a general reference.
Verification references: Wikipedia, Solubility table; ChemWhiz course values.