In this post, we will determine the oxidation numbers in hydroxylamine, NH₂OH.

To determine the oxidation number of an atom(s) in a molecule or an ion, start with the known oxidation numbers and the rules summarized below:

 

 

Keep in mind that the summary is zero for neutral molecules and is equal to the charge for ions.

For NH₂OH, the elements with standard oxidation states are oxygen (-2), and hydrogen (+1), so we need to determine the oxidation state of the nitrogen. 

Assign x for the oxidation state of N and set up an equation:

1(x) + 2(+1) + 1(-2) + 1(+1)= 0

x + 2 -2 +1= 0

x = -1

We can also assign the oxidation state of the hydroxide ion -1 as if it is a monoatomic ion (rule 2), and set up another equation:

1(x) + 2(+1) + 1(-1) = 0

x = -1

 

Further Reading

• Solutions
• Strong and Weak Electrolytes
• Dissociation of Ionic Compounds
• Molecular, Ionic, and Net Ionic Equations
• Molarity 
• Dilution
• Ion Concentration
• Precipitation Reactions
• Definitions of Acids and Bases
• Naming Acids and Bases
• Acid-Base Reactions
• Displacement Reactions
• Predicting The Products of Chemical Reactions
• Stoichiometry of Reactions in Aqueous Solutions
• Acid-Base Titrations
• Oxidation State
• Oxidation-Reduction (Redox) Reactions

• Balancing Redox Reactions
  Reactions in Aqueous Solutions – Practice Problems

 

More examples of the oxidation state in this multiple-choice quiz: