Which one of the following is formed apart from sodium chloride when chlorine reacts with hot concentrated sodium hydroxide?

Options

A. `NaClO`
B. `NaClO_2`
C. `NaClO_3`
D. `NaClO_4`

Answer

To solve the question of what is formed apart from sodium chloride when chlorine reacts with hot concentrated sodium hydroxide, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in this reaction are chlorine (Cl2) and hot concentrated sodium hydroxide (NaOH).

2. **Understand the Type of Reaction**: The reaction between chlorine and sodium hydroxide is a disproportionation reaction. In this type of reaction, one element is simultaneously oxidized and reduced.

3. **Write the Balanced Reaction**: The balanced chemical equation for the reaction is:
\[ 3 Cl_2 + 6 NaOH \rightarrow 5 NaCl + NaClO_3 + 3 H_2O \]
In this equation, we can see that sodium chloride (NaCl) and sodium chlorate (NaClO3) are produced.

4. **Determine the Oxidation States**:
- In Cl2, the oxidation state of chlorine is 0.
- In NaCl, the oxidation state of chlorine is -1.
- In NaClO3, the oxidation state of chlorine is +5.

5. **Conclusion**: From the reaction, apart from sodium chloride (NaCl), sodium chlorate (NaClO3) is also formed. Therefore, the answer to the question is sodium chlorate (NaClO3).

### Final Answer:
Apart from sodium chloride, sodium chlorate (NaClO3) is formed when chlorine reacts with hot concentrated sodium hydroxide.

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