When one formula unit of CaCl_2 dissolves completely in water, how many individual ions are produced?

• A. 2 ions
• B. 3 ions
• C. 4 ions
• D. 1 ion

Answer: (B)

Verified step by step guidance

1. Identify the chemical formula of the compound: CaCl_2 consists of one calcium ion (Ca^{2+}) and two chloride ions (Cl^{-}).
2. Understand that when CaCl_2 dissolves in water, it dissociates completely into its constituent ions.
3. Write the dissociation equation: \(\text{CaCl}_2 (s) \rightarrow \text{Ca}^{2+} (aq) + 2\text{Cl}^{-} (aq)\).
4. Count the total number of ions produced from one formula unit: 1 Ca^{2+} ion + 2 Cl^{-} ions = 3 ions.
5. Conclude that dissolving one formula unit of CaCl_2 produces 3 individual ions in solution.