To solve the question regarding the reaction of `Cl_2`, `Br_2`, or `I_2` with cold and dilute alkali solutions, we can follow these steps:
### Step-by-Step Solution
1. **Identify the Reactants**: The reactants in this case are chlorine (`Cl_2`), bromine (`Br_2`), or iodine (`I_2`), and they are reacting with a cold and dilute alkali solution, which is typically sodium hydroxide (`NaOH`).
2. **Understand the Reaction Conditions**: The reaction occurs under cold and dilute conditions, which influences the products formed.
3. **Write the General Reaction for Chlorine**:
- When chlorine reacts with cold and dilute sodium hydroxide, the products formed are sodium chloride (`NaCl`), sodium hypochlorite (`NaOCl`), and water (`H_2O`).
- The balanced equation can be written as:
\[
Cl_2 + 2NaOH \rightarrow NaCl + NaOCl + H_2O
\]
4. **Write the General Reaction for Bromine**:
- Similarly, when bromine reacts with cold and dilute sodium hydroxide, the products formed are sodium bromide (`NaBr`), sodium hypobromite (`NaBrO`), and water.
- The balanced equation can be written as:
\[
Br_2 + 2NaOH \rightarrow NaBr + NaBrO + H_2O
\]
5. **Write the General Reaction for Iodine**:
- For iodine, the reaction with cold and dilute sodium hydroxide produces sodium iodide (`NaI`), sodium hypoiodite (`NaIO`), and water.
- The balanced equation can be written as:
\[
I_2 + 2NaOH \rightarrow NaI + NaIO + H_2O
\]
6. **Summarize the Products**: From the reactions, we can summarize that:
- Chlorine produces: Sodium chloride (`NaCl`), Sodium hypochlorite (`NaOCl`), and water (`H_2O`).
- Bromine produces: Sodium bromide (`NaBr`), Sodium hypobromite (`NaBrO`), and water (`H_2O`).
- Iodine produces: Sodium iodide (`NaI`), Sodium hypoiodite (`NaIO`), and water (`H_2O`).
7. **Conclusion**: Therefore, the general products formed when `Cl_2`, `Br_2`, or `I_2` react with cold and dilute alkali solution are halides, hypohalides, and water.
### Final Answer
The reaction of `Cl_2`, `Br_2`, or `I_2` with cold and dilute alkali solution forms halides, hypohalides, and water.
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