Question

Hydrochloric acid is not soluble in toluene, a nonpolar solvent but quite soluble in water. What can be inferred about the nature of the acid?

Answer 1

That it's a polar compound.

Explanation:

Likes dissolve in likes.

Hydrochloric acid not only dissolves in water, but it dissociates:
`HCl->H^+ +Cl^-`

The `H^+` attaches to a water molecule to form hydronium:
`HCl+H_2O->H_3O^+ +Cl^-`

Where the hydronium is causing the acidity.