Among the following molecules, in which does bromine show the maximum oxidation state?

Options

A. `Hg_(2)(BrO_(3))_(2)`
B. `Br-Cl`
C. `KBrO_(4)`
D. `Br_(2)`

Answer

To determine in which molecule bromine shows the maximum oxidation state, we will analyze the oxidation states of bromine in each of the given compounds step by step.

### Step 1: Analyze Hg2BrO3
1. **Identify oxidation states**:
- Mercury (Hg) has an oxidation state of +1.
- Oxygen (O) has an oxidation state of -2.
- Let the oxidation state of bromine (Br) be \( x \).

2. **Set up the equation**:
- The compound is neutral, so the sum of oxidation states must equal 0.
- The formula for the oxidation states is:
\[ 2(+1) + 2(x) + 3(-2) = 0 \]
- Simplifying gives:
\[ 2 + 2x - 6 = 0 \implies 2x - 4 = 0 \implies 2x = 4 \implies x = +2 \]

### Step 2: Analyze BrCl
1. **Identify oxidation states**:
- Chlorine (Cl) has an oxidation state of -1.
- Let the oxidation state of bromine (Br) be \( x \).

2. **Set up the equation**:
- The compound is neutral:
\[ x + (-1) = 0 \implies x = +1 \]

### Step 3: Analyze KBrO4
1. **Identify oxidation states**:
- Potassium (K) has an oxidation state of +1.
- Oxygen (O) has an oxidation state of -2.
- Let the oxidation state of bromine (Br) be \( x \).

2. **Set up the equation**:
- The compound is neutral:
\[ +1 + x + 4(-2) = 0 \]
- Simplifying gives:
\[ 1 + x - 8 = 0 \implies x - 7 = 0 \implies x = +7 \]

### Step 4: Analyze Br2
1. **Identify oxidation states**:
- In its elemental state, bromine (Br2) has an oxidation state of 0.

### Step 5: Compare oxidation states
- From the calculations:
- In Hg2BrO3, Br = +2
- In BrCl, Br = +1
- In KBrO4, Br = +7
- In Br2, Br = 0

### Conclusion
The maximum oxidation state of bromine among the given compounds is **+7** in **KBrO4**.

### Final Answer
The molecule in which bromine shows the maximum oxidation state is **KBrO4** (Option C).

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