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.
Reading how much solute saturates water at a temperature, plus recrystallization and precipitation-on-cooling.
Grams of solute per 100 g water, 0 °C to 100 °C.
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 salt per 100 g of water. Numbered additions have sources below; ≈ identifies evaluated recommendations or research-fit estimates. Chart readouts are approximate.
| 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 | 81.6 [1] | 85.5 | 91.3 [1] | 94.9 | 99.2 | 104 |
| Potassium chlorate | KClO3 | 3.3 | 5.2 | 7.3 | 10.1 | 13.9 | ≈ 18.4 [3] | 23.8 | ≈ 30.0 [3] | 37.5 | 46 | 56.3 |
| Potassium chloride | KCl | 28 | 31.2 | 34.2 | 37.2 | 40.1 | 42.6 | 45.8 | 48.7 [2] | 51.3 | 53.9 | 56.3 |
| Potassium iodide | KI | 128 | 136 | 144 | 153 | 162 | 169.9 [2] | 176 | 183.9 [2] | 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 | ≈ 114.4 [4] | 122 | ≈ 135.7 [4] | 148 | ≈ 160.9 [4] | 180 |
| Sodium sulfate | Na2SO4 | 4.9 | 9.1 | 19.5 | 40.8 | 48.8 | ≈ 46.5 [5] | 45.3 | ≈ 44.3 [5] | 43.7 | 42.7 | 42.5 |
Important Notes
- Values are grams of anhydrous salt per 100 g of water, not per 100 g of solution. Unmarked values retain the rounded ChemWhiz course compilation. Numbered values fill its gaps: [1] and [2] are published measurements converted from mass percent; ≈ marks evaluated recommendations or research-fit estimates, not measurements at that exact temperature.
- Added measurements: KBr at 50 and 70 °C [1]; KI at 50 and 70 °C and KCl at 70 °C [2]. Mass percentages w were converted using 100w/(100 − w). Values are rounded to 0.1 g; small differences between sources are expected.
- Approximate additions: KClO3 at 50 and 70 °C [3], from recommendations at 50.05 and 70.05 °C; NaNO3 at 50, 70 and 90 °C [4], from an evaluated mole-fraction fit; Na2SO4 at 50 and 70 °C [5], from the anhydrous-salt molality fit.
- The chart passes through every listed numeric value and uses smooth interpolation between points. Its readouts are approximate, including between temperatures; the curve is not an additional experimental measurement.
- Most ionic solids dissolve more at higher temperature (steeply for KNO3, barely for NaCl). Sodium sulfate is the classic exception: its solubility peaks near the Na2SO4·10H2O to Na2SO4 transition at 32.4 °C and then falls (retrograde solubility). The 10 °C chart grid does not resolve the exact transition or peak; below it the solid is hydrated, but the quantity of dissolved salt is expressed as anhydrous Na2SO4.
- 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; [1] Pinho and Macedo (2002), Table 1; [2] Martins et al. (2023), Table 2; [3] IUPAC Solubility Data Series, volume 30 (1987), page 107, Table 2; [4] Voigt (2026), equation 13; [5] Krumgalz (2018), equation 1 and Table 1.