Question

Substance A will not dissolve in water. What can be said about substance A?

Answer 1

That it will not dissolve in water..........

Explanation:

Substance A could be molecular, i.e. it could be an organic species. It could also be an ionic solute that is water insoluble. Many hydroxides, phosphates, sulfides, oxides fit this description. More data are required.

Answer 2

substance A is non-polar or water-insoluble

Explanation:

Substance A must be non-polar or "in-soluble" if it is does not dissolve in water. Remember that "likes dissolves likes" when it comes to the polarity of substances. Polar solvents (e.g. water) dissolve polar solutes (e.g. salts, sugars). If water cannot dissolve substance A, that means that substance A is water-insoluble or is non-polar.

Substance A could be a molecular substance since most molecular substances are non-polar.
OR
Substance A could be an ionic compound. Some ionic compounds are water-insoluble. Look at the following solubility rules.