What is the bromine highest oxidation state here? Write it down: (a) Br2 _ _ _ (b) BrCl3 _ _ _ (C) NaOBr _ _ _ (
The Correct Answer and Explanation is:
Here are the correct answers and a detailed explanation for each compound:
Answers:
(a) Br₂ → 0
(b) BrCl₃ → +3
(c) NaOBr → +1
Explanation:
Oxidation state (also called oxidation number) is a concept that helps chemists track electron transfer in compounds and reactions. It represents the hypothetical charge an atom would have if all bonds to atoms of different elements were 100% ionic.
Let’s examine each compound:
(a) Br₂ (Bromine molecule):
In Br₂, bromine exists as a diatomic element, meaning it is composed of two bromine atoms bonded together. Since the atoms are identical, the electrons are shared equally.
- Therefore, each bromine atom has an oxidation state of 0.
- This is because elements in their elemental form always have an oxidation state of zero.
Oxidation state of Br in Br₂ = 0
(b) BrCl₃ (Bromine trichloride):
In BrCl₃, bromine is bonded to three chlorine atoms. Chlorine is more electronegative than bromine, so each Cl “pulls” electrons away from Br.
- Chlorine typically has an oxidation state of –1.
- There are 3 chlorine atoms, contributing a total of –3.
To balance the overall neutral charge:
- Let Br’s oxidation state be x
- x + 3(–1) = 0
- x – 3 = 0
- x = +3
Oxidation state of Br in BrCl₃ = +3
(c) NaOBr (Sodium hypobromite):
This is an ionic compound made of Na⁺, O²⁻, and Br in a polyatomic ion. The key part is the hypobromite ion (OBr⁻).
- Na is a group 1 metal, so it has an oxidation state of +1.
- Oxygen (O) typically has an oxidation state of –2.
- The overall charge of the OBr⁻ ion is –1.
Let Br’s oxidation state be x:
x + (–2) = –1
x = +1
Oxidation state of Br in NaOBr = +1
Summary:
| Compound | Oxidation State of Br |
|---|---|
| (a) Br₂ | 0 |
| (b) BrCl₃ | +3 |
| (c) NaOBr | +1 |
This demonstrates that the oxidation state of bromine varies depending on the chemical environment, ranging from 0 (elemental form) to positive values when bonded with more electronegative atoms like oxygen or chlorine.
