Why is water an excellent solvent for most ionic compounds and polar covalent molecules but not for non-polar compounds?
a) water is a polar molecule.
b) water has a charge like an ion.
c) water is a deionizing substance.
d) water molecules have an unusually high kinetic energy in the liquid state.

A)Water is a polar molecule. 

When talking about solubility, the rule that "like dissolves like" is usually correct. This means that polar substances are soluble in other polar substances. This occurs because the opposite partially charged ends of different polar molecules are attracted to each other. Similarly, the partially charged ends of polar molecules will be even more attracted to the charged ends of an ionic compound's molecule. This is why,for example, table salt/ NaCl, which is an ionic compound, dissolves in water.