Heat of Dissolution Calculator
Calculate the heat energy change when a solute dissolves in a solvent, including temperature changes and endothermic/exothermic classification. Perfect for chemistry labs, pharmaceutical compounding, and thermal analysis.
Dissolution Parameters
Dissolution Heat Results
Error
Select substance and enter parameters to calculate dissolution heat
Understanding Heat of Dissolution
Heat of dissolution is the energy change that occurs when a solute dissolves in a solvent. This process can be either exothermic (heat is released) or endothermic (heat is absorbed), depending on the substances involved. Understanding dissolution heat is crucial in chemistry labs, pharmaceutical manufacturing, and thermal analysis.
The heat of dissolution depends on the amount of solute, the enthalpy of solution, and the solvent properties. Some substances like sodium chloride release heat when dissolving, while others like ammonium nitrate absorb heat from their surroundings.
Heat of Dissolution Formula
Alternative: Q = Moles × (Heat kJ/mol)
The formula shows that the total heat change is directly proportional to the amount of solute dissolving. The heat of dissolution is a characteristic property measured in energy per unit mass or per mole.
Dissolution Heat Examples
| Substance | Mass (kg) | Heat (kJ/kg) | Solvent (kg) | ΔT (°C) |
|---|---|---|---|---|
| NaCl | 1.0 | 3.9 | 5 | 0.09 |
| KCl | 2 | 17.2 | 6 | 0.95 |
| Ammonium nitrate | 1.5 | –25.7 | 4 | –2.41 |
| Sugar | 3 | 5.6 | 8 | 0.21 |
| Custom | 0.8 | 12 | 3 | 1.00 |
| Potassium sulfate | 1.2 | 24.3 | 7 | 1.17 |
| Sodium carbonate | 0.9 | 14.2 | 4.5 | 0.85 |
| Ammonium sulfate | 2.1 | –6.1 | 5.5 | –0.58 |
| Calcium chloride | 1.6 | –81.3 | 3.2 | –20.33 |
| Magnesium sulfate | 1.3 | 13.3 | 6.2 | 0.70 |
| Sodium nitrate | 1.7 | 20.4 | 8.1 | 1.29 |
| Potassium nitrate | 2.3 | 34.9 | 9.2 | 3.54 |
| Sodium hydroxide | 0.5 | –44.5 | 2.1 | –5.29 |
| Potassium hydroxide | 1.4 | –57.6 | 4.3 | –7.47 |
| Ammonium chloride | 0.7 | 16.3 | 3.8 | 0.75 |
| Sodium bicarbonate | 1.1 | –9.2 | 5.8 | –0.58 |
| Copper sulfate | 0.8 | –66.5 | 2.7 | –7.35 |
| Zinc chloride | 1.9 | –38.3 | 6.4 | –4.54 |
| Ferric chloride | 0.6 | –55.2 | 3.1 | –5.35 |
| Aluminum sulfate | 2.4 | –17.6 | 7.3 | –2.32 |
| Barium chloride | 1.8 | 8.8 | 8.7 | 0.73 |
| Lithium chloride | 0.4 | –37.0 | 2.3 | –3.22 |
| Nickel chloride | 1.0 | –72.8 | 4.2 | –8.66 |
| Strontium chloride | 2.2 | –18.6 | 9.1 | –1.87 |
These examples show how different substances affect solution temperature during dissolution. Positive ΔT values indicate exothermic dissolution (solution warms), while negative values indicate endothermic dissolution (solution cools).
How to Calculate Dissolution Heat
- Choose the substance: Select from common substances or enter custom heat values
- Determine the amount: Enter mass in kg or moles of solute
- Specify the solvent: Enter solvent mass or volume
- Apply the formula: Calculate heat energy and temperature change
This calculator automatically handles unit conversions and detects whether the dissolution process is endothermic or exothermic based on the sign of the heat value.
Heat of dissolution calculations are essential in pharmaceutical compounding, chemical processing, and laboratory work where precise thermal management of dissolution processes is required.