What is the typical oxidation number of oxygen in most compounds?

• A. 0
• B. -2
• C. +2
• D. -1

Answer: (B)

Verified step by step guidance

1. Understand that the oxidation number (or oxidation state) is a hypothetical charge assigned to an atom in a compound, assuming that electrons in all chemical bonds belong entirely to the more electronegative atom.
2. Recall that oxygen is highly electronegative and typically gains electrons when forming compounds, which usually results in a negative oxidation number.
3. Know the common oxidation states of oxygen: in most compounds, oxygen has an oxidation number of -2. This is because oxygen usually forms two bonds and gains two electrons relative to its elemental state.
4. Be aware of exceptions: in peroxides (like H2O2), oxygen has an oxidation number of -1, and in compounds with fluorine (like OF2), oxygen can have a positive oxidation number, such as +2.
5. Therefore, the typical oxidation number of oxygen in most compounds is -2.