Consider three P, Q, R, salts among them P and Q salts have different cations annd also have different coloured polyatomic anion due to charge transfer phenomenon while P and R salts have same cation but have different anions. Salts R decomposes into an acidic gas an a basic gas.
Q. Salt P decomposes on heating into a coloured solid, neutral gas a neutral vapour, then which of the following can not be the product of salt P after decomposition?

Options

A. `N_(2)`
B. `Cr_(2)O_(3)`
C. `I_(2)`
D. `H_(2)O`

Explanation

To solve the question regarding the decomposition of salt P, we will analyze the information provided step by step.

### Step 1: Understand the properties of salt P
We know that salt P decomposes upon heating into:
- A colored solid
- A neutral gas
- A neutral vapor

### Step 2: Identify the possible products
Given the decomposition products, we need to think of a salt that fits this description. The example given in the video is ammonium dichromate (NH4Cr2O7), which decomposes as follows:
\[ \text{NH}_4\text{Cr}_2\text{O}_7 \rightarrow \text{N}_2 + \text{Cr}_2\text{O}_3 + \text{H}_2\text{O} \]
Here:
- **N2** is the neutral gas.
- **Cr2O3** is the colored solid (chromium(III) oxide).
- **H2O** is the neutral vapor.

### Step 3: Evaluate the options
Now, we need to evaluate the given options to determine which product cannot be formed from the decomposition of salt P:
1. **N2** - This is produced in the decomposition.
2. **Cr2O3** - This is also produced in the decomposition.
3. **I2** - This is not produced in the decomposition.
4. **H2O** - This is produced in the decomposition.

### Step 4: Conclusion
From the analysis, we see that the only product that cannot be formed from the decomposition of salt P is **I2** (iodine). Therefore, the correct answer is option 3.

### Final Answer
**I2 cannot be the product of salt P after decomposition.**

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