Why are nitrates always soluble?

1 Answer
Nov 28, 2015

This is largely an entropy phenomenon. The nitrate ion is not very charge dense, and the negative charge is distributed over 4 centres.


Because the nitrate is not charge dense, the species in solution is less polarizing (as the nitrate ion, #NO_3^-#), and causes less solvent order upon dissolution. For this reason, many nitrate salts have solubility in non-aqueous solvents. Inorganic chemists generally do not exploit this solubility, because the nitrate ion is still a potent oxidant, although in the aqueous phase this reactivity is somewhat masked.