How can I calculate solubility of potassium nitrate?

1 Answer
Jul 28, 2014

The only way to determine the solubility of potassium nitrate is to do an experiment or interpolate from a solubility graph.


Solubility is the mass of a solute that can be dissolved in a given mass of solvent.

Solubility varies according to temperature for the same solute and solvent.

The solubility graph for potassium nitrate in water is shown below.


What is the solubility of potassium nitrate at 50 °C?


Read along the horizontal axis until you reach 50 °C. From there, extend a line upwards until it meets the graph.

Then extend a horizontal line to the vertical axis. Read the temperature at that point.

The solubility is about 90 g of KNO₃ per 100 g of water.