What is the oxidation number of bromine in the molecule H2Br2O6?

• A. -1
• B. +5
• C. +1
• D. +3

Answer: (B)

Verified step by step guidance

1. Identify the atoms present in the molecule H2Br2O6 and their typical oxidation states. Hydrogen (H) usually has an oxidation number of +1, and oxygen (O) usually has an oxidation number of -2.
2. Assign oxidation numbers to hydrogen and oxygen atoms: For 2 hydrogen atoms, total oxidation number is 2 × (+1) = +2; for 6 oxygen atoms, total oxidation number is 6 × (-2) = -12.
3. Let the oxidation number of bromine (Br) be x. Since there are 2 bromine atoms, their total contribution to the oxidation number is 2x.
4. Write the equation for the sum of oxidation numbers in the neutral molecule, which must equal zero: 2(+1) + 2x + 6(-2) = 0.
5. Solve the equation for x: 2 + 2x - 12 = 0, which simplifies to 2x - 10 = 0, and then 2x = 10, so x = +5. This means the oxidation number of bromine in H2Br2O6 is +5.