Solubility curves

The program holds the solubility of potassium nitrate and of common salt, in grams in $100\ \text{g}$ of water, at six temperatures, and draws both curves. You will find the crystals that form when a solution saturated at $80\ ^\circ\text{C}$ is cooled to $20\ ^\circ\text{C}$, for each salt, and the first temperature in the table at which potassium nitrate is the more soluble.

The idea. Cooling a saturated solution makes the extra solute crystallise: the crystals are the drop in solubility.

Your tasks.

1. Find kno3_crystals, the grams of potassium nitrate that crystallise from $100\ \text{g}$ of water cooled from $80\ ^\circ\text{C}$ to $20\ ^\circ\text{C}$.
2. Find nacl_crystals, the same for common salt.
3. In the loop, set first to the first temperature at which potassium nitrate dissolves more than salt.