Which of the following representations correctly shows the species present when calcium chloride (CaCl_2) is dissolved in water?

• A. Solid CaCl_2 particles floating in water
• B. Only Ca^{2+} ions present, with no Cl^{-} ions
• C. Ca^{2+} ions and Cl^{-} ions dispersed throughout the solution
• D. CaCl_2 molecules remaining intact in solution

Answer: (C)

Verified step by step guidance

1. Understand that calcium chloride (CaCl_2) is an ionic compound composed of Ca^{2+} cations and Cl^{-} anions.
2. Recall that when ionic compounds dissolve in water, they dissociate into their constituent ions due to the polar nature of water molecules.
3. Write the dissociation equation for CaCl_2 in water: \(\mathrm{CaCl_2 (s) \rightarrow Ca^{2+} (aq) + 2Cl^{-} (aq)}\).
4. Recognize that in solution, Ca^{2+} and Cl^{-} ions are dispersed and surrounded by water molecules, not existing as solid particles or intact molecules.
5. Conclude that the correct representation shows both Ca^{2+} and Cl^{-} ions dispersed throughout the solution, indicating complete dissociation.