A compound that dissolves in water to form an ionic solution is a salt. Salts are composed of positively charged ions (cations) and negatively charged ions (anions). When a salt dissolves in water, the water molecules surround and separate the ions, allowing them to move freely in solution. The resulting solution is called an electrolyte, and it can conduct electricity because the ions are free to move.

Some examples of salts that dissolve in water to form ionic solutions include sodium chloride (NaCl), potassium nitrate (KNO3), and copper sulfate (CuSO4). When these salts dissolve in water, the sodium, potassium, and copper ions become positively charged, while the chloride, nitrate, and sulfate ions become negatively charged. The ions then move freely in solution, allowing the solution to conduct electricity.