Question

The oxidation state of bromine in $HOBrO_2$ oxoacid is ________.

• A. + 7
• B. + 5
• C. + 3
• D. + 1

Hint:

Always simplify the molecular formula first. $HOBrO_n$ represents halic acids where the oxidation state of the halogen is usually $(2n + 1) - 2$ (accounting for the H). For $n=2$, it is $2(2)+1 = 5$.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The oxidation state is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic.
For a neutral molecule, the sum of oxidation states of all atoms must be zero.
Step 2: Key Formula or Approach:
The chemical formula \(HOBrO_2\) is equivalent to \(HBrO_3\) (bromic acid).
Let the oxidation state of \(Br\) be \(x\).
Oxidation state of \(H = +1\)
Oxidation state of \(O = -2\)
Step 3: Detailed Explanation:
Sum of oxidation states = 0
\[ (+1) + x + 3 \times (-2) = 0 \]
\[ 1 + x - 6 = 0 \]
\[ x - 5 = 0 \]
\[ x = +5 \]
Step 4: Final Answer:
The oxidation state of bromine in \(HOBrO_2\) is \(+5\).