What is the most KNO3 that can be dissolved in 250 mL of water at 45°C?
The solubility graph is a very useful tool because it tells you the amount of potassium nitrate that can be dissolved per 100 mL
of water in order to have a saturated solution of potassium nitrate at a given temperature.
In order to find the solubility of the salt at 60
∘C, start from the 60∘C
mark on the graph and move up until you intersect the curve. At the point of intersection, move left until you intersect the y
axis and read off the value that you land on.
In this case, you can estimate that the solubility of potassium nitrate in water at 60∘C
is equal to about
solubility ≈ 110 g / 100 mL water
This tells you that a saturated solution of potassium nitrate will hold about 110 g
of dissolved salt, i.e. of dissociated salt, per 100 mL
of water at 60∘C