`CaOCl_(2)+NaI+HCl to __________+CaCl_(2)+H_2O+NaCl`

Answer

To solve the question, we need to identify the missing compound in the reaction involving calcium oxychloride (CaOCl₂), sodium iodide (NaI), and hydrochloric acid (HCl). The products of this reaction are calcium chloride (CaCl₂), water (H₂O), sodium chloride (NaCl), and the missing compound, which we will determine step by step.

### Step-by-Step Solution:

1. **Identify Reactants and Products**:
- Reactants: CaOCl₂, NaI, HCl
- Products: CaCl₂, H₂O, NaCl, and an unknown compound.

2. **Understand the Reaction**:
- Calcium oxychloride (CaOCl₂) can react with sodium iodide (NaI) and hydrochloric acid (HCl).
- The reaction will likely involve the displacement of iodine (I) and the formation of iodine gas (I₂).

3. **Write the Chemical Equation**:
- The unbalanced equation can be written as:
\[ \text{CaOCl}_2 + \text{NaI} + \text{HCl} \rightarrow ? + \text{CaCl}_2 + \text{H}_2\text{O} + \text{NaCl} \]

4. **Predict the Missing Compound**:
- From the reaction, we can predict that iodine (I) is released as a diatomic molecule (I₂).
- Thus, the missing compound is I₂.

5. **Balance the Chemical Equation**:
- The balanced equation will look like this:
\[ \text{CaOCl}_2 + 2\text{NaI} + 2\text{HCl} \rightarrow \text{I}_2 + \text{CaCl}_2 + 2\text{H}_2\text{O} + 2\text{NaCl} \]
- Here, we have balanced the number of atoms on both sides of the equation.

6. **Final Answer**:
- The missing compound in the reaction is I₂.

### Final Answer:
\[ \text{CaOCl}_2 + \text{NaI} + \text{HCl} \rightarrow \text{I}_2 + \text{CaCl}_2 + \text{H}_2\text{O} + \text{NaCl} \]