Redox Reactions Worksheet

What happens during oxidation in a redox reaction?

• Gain of electrons

• Loss of electrons

• Gain of protons

• Loss of protons

In a redox reaction, which species is considered reduced?

• The species that loses electrons

• The species that gains electrons

• The species that loses protons

• The species that gains protons

What is the oxidation number of a free element?

• 0

• +1

• -1

• +2

Which statement correctly describes the oxidation number of a monatomic ion?

• It equals the charge of the ion.

• It is always zero.

• It is always +1.

• It is always -2.

What is the sum of the oxidation numbers in a neutral compound?

• 0

• +1

• -1

• +2

Group 1 metals typically have which oxidation number?

• +1

• 0

• +2

• -1

In which situation does hydrogen have an oxidation number of -1?

• In metal hydrides

• In peroxides

• In free elements

• In Group 1 metals

Oxygen usually has an oxidation number of -2. In which type of compound does it have an oxidation number of -1?

• In peroxides

• In metal hydrides

• In free elements

• In Group 2 metals

A compound contains sodium (Na), hydrogen (H), and oxygen (O). Using the rules for assigning oxidation numbers, what is the oxidation number of sodium in this compound?

• +1

• 0

• -1

• +2

If the sum of oxidation numbers in a polyatomic ion is not zero, what does it equal?

• The charge on the species

• Always +1

• Always -2

• The number of atoms in the ion