What happens when `Cl_2` gas is passed through a mixture of NaF, NaBr and Nal?

Options

A. `F_2 and I_2` are evolved
B. Only `F_2` is liberated
C. `Br_2 ` and `I_2` are liberated
D. Only `Br_2 ` is liberated

Explanation

To determine what happens when Cl₂ gas is passed through a mixture of NaF, NaBr, and NaI, we need to analyze the reactivity of chlorine in relation to the halides present in the mixture.

### Step-by-Step Solution:

1. **Understanding Reactivity of Halogens**:
- Halogens have different reactivities, which follow the trend: Fluorine (F) > Chlorine (Cl) > Bromine (Br) > Iodine (I). This means that a more reactive halogen can displace a less reactive halogen from its compound.

2. **Reaction with NaF**:
- When Cl₂ is passed through NaF, chlorine cannot displace fluorine because fluorine is more reactive than chlorine. Therefore, no reaction occurs with NaF.

3. **Reaction with NaBr**:
- When Cl₂ is passed through NaBr, chlorine can displace bromine because chlorine is more reactive than bromine. The reaction can be represented as:
\[ \text{Cl}_2 + 2 \text{NaBr} \rightarrow 2 \text{NaCl} + \text{Br}_2 \]
- In this reaction, sodium chloride (NaCl) is formed and bromine (Br₂) is liberated.

4. **Reaction with NaI**:
- When Cl₂ is passed through NaI, chlorine can also displace iodine because chlorine is more reactive than iodine. The reaction can be represented as:
\[ \text{Cl}_2 + 2 \text{NaI} \rightarrow 2 \text{NaCl} + \text{I}_2 \]
- Here, sodium chloride (NaCl) is formed and iodine (I₂) is liberated.

5. **Summary of Reactions**:
- From the above reactions, we conclude that:
- No reaction occurs with NaF.
- Bromine (Br₂) is liberated from NaBr.
- Iodine (I₂) is liberated from NaI.

6. **Final Conclusion**:
- Therefore, when Cl₂ gas is passed through a mixture of NaF, NaBr, and NaI, bromine and iodine are liberated. The correct option is C: Bromine and Iodine are liberated.