Following is incorrect statement

Options

A. Band dissociation energy of Bromie is more than that of chlorine
B. The standard electrode potential of chlorine is more thant aht of fluorine
C. In bleaching powder, the precentage of chlorine is `35-38%`.
D. All

Explanation

To solve the question of identifying the incorrect statement regarding the properties of halogens, we will analyze each statement step by step.

### Step-by-Step Solution:

1. **Analyzing Statement 1: Bond Dissociation Energy of Bromine vs. Chlorine**
- The statement claims that the bond dissociation energy of bromine (Br2) is greater than that of chlorine (Cl2).
- Bond dissociation energy is the energy required to break the bond between two atoms.
- As we move down the group from chlorine to bromine, the atomic size increases due to the addition of electron shells.
- A larger atomic size leads to a longer bond length, which results in weaker bonds.
- Therefore, the bond dissociation energy of Cl2 is actually greater than that of Br2.
- **Conclusion**: This statement is **incorrect**.

2. **Analyzing Statement 2: Standard Electrode Potential of Chlorine vs. Fluorine**
- The statement claims that the standard electrode potential is greater for chlorine than for fluorine.
- The standard electrode potential relates to the tendency of a species to gain electrons (reduction).
- Fluorine (F2) has a higher reduction potential than chlorine (Cl2) due to its smaller size and stronger tendency to gain electrons.
- Therefore, the statement is **incorrect**.

3. **Analyzing Statement 3: Percentage of Chlorine in Bleaching Powder**
- The statement discusses the percentage of chlorine in bleaching powder (Ca(OCl)2).
- To calculate the percentage of chlorine, we find the molar mass of Ca(OCl)2:
- Calcium (Ca) = 40 g/mol
- Oxygen (O) = 16 g/mol (2 O = 32 g/mol)
- Chlorine (Cl) = 35.5 g/mol (2 Cl = 71 g/mol)
- Total molar mass = 40 + 32 + 71 = 143 g/mol
- The percentage of chlorine is calculated as:
\[ \text{Percentage of Cl} = \left(\frac{71}{143}\right) \times 100 \approx 49.65\% \]
- The statement that claims a specific percentage (55.55%) is incorrect based on this calculation.

4. **Final Conclusion:**
- All three statements analyzed are incorrect. However, the first statement is the one specifically asked for in the question.

### Summary of Incorrect Statements:
- Statement 1: Incorrect (Br2 has lower bond dissociation energy than Cl2).
- Statement 2: Incorrect (F2 has a higher standard electrode potential than Cl2).
- Statement 3: Incorrect (Percentage of chlorine in bleaching powder is approximately 49.65%).