If CaCl2 is dissolved in water, what will happen?

• A. CaCl2 will partially dissolve, with some remaining as a solid.
• B. CaCl2 will form a precipitate and not dissolve.
• C. CaCl2 will completely dissociate into Ca^{2+} and Cl^{-} ions.
• D. CaCl2 will react with water to produce CaO and HCl.

Answer: (C)

Verified step by step guidance

1. Recognize that CaCl2 is an ionic compound composed of Ca^{2+} cations and Cl^{-} anions.
2. Understand that when ionic compounds like CaCl2 dissolve in water, they typically dissociate into their constituent ions due to the polar nature of water molecules.
3. Write the dissociation equation for CaCl2 in water: \(\mathrm{CaCl_2 (s) \rightarrow Ca^{2+} (aq) + 2Cl^{-} (aq)}\).
4. Note that CaCl2 is highly soluble in water, so it will completely dissociate rather than partially dissolve or form a precipitate.
5. Recognize that CaCl2 does not chemically react with water to form CaO and HCl; instead, it simply dissociates into ions.