Oxidation Number Chemistry Example 3

Follow the full solution, then compare it with the other examples linked below.

Example 3

easy
What is the oxidation number of nitrogen in NO3−\text{NO}_3^-?

Solution

  1. 1
    Let N = xx, O = −2-2. The ion has a charge of −1-1.
  2. 2
    x+3(−2)=−1⇒x−6=−1⇒x=+5x + 3(-2) = -1 \Rightarrow x - 6 = -1 \Rightarrow x = +5.

Answer

N: +5\text{N: } +5
For polyatomic ions, the sum of oxidation numbers must equal the charge of the ion, not zero.

About Oxidation Number

A number assigned to each atom in a compound using a set of rules, representing the hypothetical charge that atom would carry if all bonds.

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More Oxidation Number Examples

Example 1 easy

Assign oxidation numbers to each element in [formula].

Example 2 medium

Assign oxidation numbers to each atom in [formula] and determine the oxidation number of manganese.

Example 4 hard

In the reaction [formula], determine the oxidation number of iron and carbon on each side. Which ele

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