Oxidation-Reduction Ch 16

A substance that oxidizes another substance by accepting its electron is called an oxidizing agent.

• True

• False

Oxidation and reduction are complementary - as an atom is oxidized, another atom is reduced.

• True

• False

Electrons are lost during reduction.

• True

• False

An oxidation reaction occurs only in the presence of _____.

• oxygen

• hydrogen

• a metal

• a reduction reaction

When an element is reduced, its oxidation number _____.

• stays the same

• decreases

• increases

• may increase or decrease

The substance that is oxidized in the reaction Fe₂O₃ + 2Al → Al₂O₃ + 2Fe is _____.

• Al

• Fe

An element or compound losing electrons to a more electronegative element is _____.

• oxidation

• reduction

• redox

• combination

For every oxidation reaction that occurs, a _____ reaction must also take place.

• combustion

• decomposition

• reduction

• synthesis

Electrons gained and lost during a redox reaction can be determined by examining the _____ of the elements involved.

• symbols

• oxidation number

• formulas

• coefficients

In the equation Al + Cl₂ → AlCl₃, the oxidation number of Al changes from _____ to _____.

• 0, 3+

• 3+, 0

• 0, 1-

• -1, 0