Solubility from Ksp

You will write a function that finds the molar solubility of any salt $\text{A}_x\text{B}_y$ from its $K_{sp}$. Then you will sort some salts by how much of each dissolves, and decide whether a mixture gives a precipitate.

The idea. $K_{sp} = x^x y^y s^{x+y}$, so $s = \left(\dfrac{K_{sp}}{x^x y^y}\right)^{1/(x+y)}$. A precipitate forms when the ionic product is larger than $K_{sp}$.

Your tasks.

1. Complete solubility(ksp, x, y) so that it returns $s$ in mol/L.
2. Set order to the names sorted from the most soluble to the least soluble.
3. Complete precipitates(ion_a, ion_b, ksp) for a salt of type AB: return True when $[\text{A}][\text{B}]$ is larger than $K_{sp}$.