Answer to Question #196904 in General Chemistry for Jay

Question

What is the most KNO3 that can be dissolved in 250 mL of water at 45°C?

Answer 1

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

.