Oxidation State Worksheet

Oxidation State Worksheet

Read each question carefully and provide your answers in the spaces provided. Show all your work for calculations.

Oxidation State (or oxidation number) is a number assigned to an element in a compound that represents the number of electrons lost or gained by an atom of that element in the compound. It helps us understand how electrons are distributed in a compound and is crucial for balancing redox reactions.

Rules for Assigning Oxidation States:

1. The oxidation state of an uncombined element is 0.

2. The oxidation state of a monatomic ion is equal to its charge.

3. In most compounds, oxygen has an oxidation state of -2 (exceptions: peroxides where it's -1, and with fluorine where it's +2).

4. In most compounds, hydrogen has an oxidation state of +1 (exception: metal hydrides where it's -1).

5. The sum of the oxidation states in a neutral compound is 0. The sum of the oxidation states in a polyatomic ion is equal to the charge of the ion.

1. What is the oxidation state of an uncombined element?

2. What is the usual oxidation state of oxygen in most compounds?

3. The sum of the oxidation states in a neutral compound is  .

4. In metal hydrides, hydrogen has an oxidation state of  .

5. Oxidation state helps us understand how   are distributed in a compound.

6. Calculate the oxidation state of sulfur (S) in H₂SO₄.

7. Determine the oxidation state of chromium (Cr) in Cr₂O₇²⁻.

8. Find the oxidation state of nitrogen (N) in HNO₃.

9. The oxidation state of a monatomic ion is always 0.

10. In the compound OF₂, oxygen has an oxidation state of -2.

11. Explain why understanding oxidation states is important in chemistry, particularly when dealing with redox reactions. Provide an example.