Oxidation Numbers

An oxidation number

• is always negative.

• is always positive.

• has no exact physical meaning.

• is the same in each compound that an element forms.

Which element has the same oxidation number in all of its compounds?

• oxygen

• fluorine

• hydrogen

• chlorine

What is the oxidation number of an atom of nitrogen in the molecule N₂?

• 0

• +3

• -3

• -6

What is the oxidation number of phosphorus in H₃PO₄?

• +1

• +4

• +5

• +8

What is the oxidation number of As in AsO₄^3-?

• +8

• +5

• -5

• -8

What is the correct Stock name for Cr(CH₃COO)₃?

• chromium acetate

• chromium triacetate

• trichromium acetate

• chromium(III) acetate

What is the correct prefix-based name for selenium(II) fluoride?

• selenium fluoride

• diselenium fluoride

• diselenium difluoride

• selenium difluoride

What is the formula for copper(I) oxide?

• CuO

• Cu₂O

• CuO₂

• Cu₂O₂

A monatomic ion has an oxidation number

• of zero.

• indicated by the ion’s prefix.

• equal to the charge of the ion.

• equal to its subscript.

What is the correct Stock name for SnBr₄?

• tin(IV) bromide

• tin bromide

• tin tetrabromide

• tin(IV) tetrabromide.