How many of the following liberate coloured vapour/gas with concentrated `H_(2)SO_(4)`?
`KCl(s)+K_(2)Cr_(2)O_(7)(s), KNO_(2)(s),Kl(s), KBr(s),KCl(s)`
`KBr(s)+MnO_(2)(s),KNO_(3),KCl(s)+MnO_(2),K_(2)SO_(3)`

Explanation

To determine how many of the given compounds liberate colored vapors or gases when reacted with concentrated sulfuric acid (H₂SO₄), we will analyze each compound and its reaction with H₂SO₄ step by step.

### Step-by-Step Solution:

1. **KCl(s) + K₂Cr₂O₇(s)**:
- Reaction: \( \text{KCl} + \text{K}_2\text{Cr}_2\text{O}_7 + 6 \text{H}^+ \rightarrow 2 \text{CrO}_2\text{Cl}_2 + 3 \text{H}_2\text{O} \)
- **Observation**: CrO₂Cl₂ is deep red in color.
- **Conclusion**: This mixture liberates colored vapors.

2. **KNO₂(s)**:
- Reaction: \( \text{KNO}_2 + 2 \text{H}^+ \rightarrow \text{HNO}_2 \) (HNO₂ is unstable and decomposes)
- Further decomposition: \( \text{HNO}_2 \rightarrow \text{HNO}_3 + \text{NO} \)
- **Observation**: NO gas reacts with oxygen to form NO₂, which is brown in color.
- **Conclusion**: KNO₂ liberates colored vapors.

3. **KI(s)**:
- Reaction: \( \text{KI} + 3 \text{H}^+ \rightarrow \text{I}_2 + \text{SO}_4^{2-} + 2 \text{H}_2\text{O} \)
- **Observation**: I₂ has violet vapors.
- **Conclusion**: KI liberates colored vapors.

4. **KBr(s)**:
- Reaction: \( 2 \text{KBr} + 2 \text{H}_2\text{SO}_4 \rightarrow \text{Br}_2 + \text{SO}_2 + 2 \text{K}^+ + 2 \text{H}_2\text{O} \)
- **Observation**: Br₂ is reddish-brown in color.
- **Conclusion**: KBr liberates colored vapors.

5. **KCl(s)**:
- Reaction: \( \text{KCl} + \text{H}_2\text{SO}_4 \rightarrow \text{HCl} + \text{SO}_4^{2-} + \text{H}_2\text{O} \)
- **Observation**: HCl is colorless.
- **Conclusion**: KCl does not liberate colored vapors.

6. **KBr(s) + MnO₂(s)**:
- Reaction: \( 2 \text{KBr} + 2 \text{H}_2\text{SO}_4 \rightarrow \text{Br}_2 + \text{SO}_2 + 2 \text{K}^+ + 2 \text{H}_2\text{O} \)
- **Observation**: Br₂ is reddish-brown in color.
- **Conclusion**: This mixture liberates colored vapors.

7. **KNO₃(s)**:
- Reaction: \( \text{KNO}_3 + 2 \text{H}_2\text{SO}_4 \rightarrow \text{NO}_2 + \text{SO}_4^{2-} + 2 \text{H}_2\text{O} \)
- **Observation**: NO₂ is brown in color.
- **Conclusion**: KNO₃ liberates colored vapors.

8. **KCl(s) + MnO₂(s)**:
- Reaction: \( 2 \text{KCl} + 2 \text{H}_2\text{SO}_4 \rightarrow \text{Cl}_2 + \text{SO}_2 + 2 \text{K}^+ + 2 \text{H}_2\text{O} \)
- **Observation**: Cl₂ is yellow-green in color.
- **Conclusion**: This mixture liberates colored vapors.

9. **K₂SO₃(s)**:
- Reaction: \( \text{K}_2\text{SO}_3 + 2 \text{H}_2\text{SO}_4 \rightarrow \text{SO}_2 + \text{K}_2\text{SO}_4 + 2 \text{H}_2\text{O} \)
- **Observation**: SO₂ is colorless.
- **Conclusion**: K₂SO₃ does not liberate colored vapors.

### Summary of Results:
- The compounds that liberate colored vapors are:
1. KCl + K₂Cr₂O₇
2. KNO₂
3. KI
4. KBr
5. KBr + MnO₂
6. KNO₃
7. KCl + MnO₂

### Final Count:
Out of the 9 compounds and mixtures, **7 liberate colored vapors**.