Answer:
Sulfur dioxide is a covalent bond because we have two non-metals (Sulfur and Oxygen).
(Sulfur dioxide formula)
It's called Sulfur dioxide but it can be called Sulfurous anhydride and Sulfur (lV) oxide.
Sulfur dioxide can have different reactions:
- In the presence of oxygen oxidation of sulfur dioxide to sulfur trioxide occurs and the formula is:

The equal is because it's a reversible equation. This reaction is spontaneous.
- The sulfur trioxide reacting with water produces sulfuric acid. The formula is:

- Also the sulfur dioxide reacting with sodium hydroxide produces sodium sulfite and the formula is:

- And finally we have the reduction of sulfur dioxide (it can be in presence of hydrogen sulfide) getting elemental sulfur and water. The formula is:
