Unit 2 - Redox - Oxidation Numbers

The oxidation number of sulfur in the sulfate ion, SO₄^2–, is

• -2

• +4

• +6

• +8

In an oxide of potassium, the oxidation number of oxygen is –½. What is the formula of this oxide?

• K₂O

• K₂O₂

• K₂O₃

• KO₂

In an oxide of nitrogen, the oxidation number of nitrogen is +4. Which is the formula of the oxide?

• N₂O

• N₂O₃

• N₂O₄

• N₂O₅

What is the oxidation number of phosphorus in the phosphate ion, PO₄^3– ?

• -3

• +3

• +5

• +7

Which name is correct for the ion SO₄²⁻ ?

• sulfate(II)

• sulfate(IV)

• sulfate(VI)

• sulfate(VIII)

What is the oxidation number of bromine in BrO₃ ⁻¹ ?

• +1

• +3

• +5

• +7

What is the oxidation number of oxygen in OF₂?

• -2

• -1

• +1

• +2

The oxidation number of sulfur in thiosulfate ions, S₂O₃^2–, is

• +2

• +3

• +4

• +6

The oxidation number of chlorine in HClO₃ is

• -1

• +3

• +5

• +7

The oxidation number of sulfur in sodium hydrogensulfide, NaHS, is

• -2

• -1

• +1

• +2