4.4 Redox

Question 1

Corrosion

Answer 1

Conversion of a metal into a metal compound by a reaction between the metal and a substance in the enviroment

Question 2

When a metal corrodes, it loses ___ and forms ___

Answer 2

electrons, cations

Question 3

Oxidation

Answer 3

Loss of electrons by a substance

Question 4

Reduction

Answer 4

When a substance gains electrons

Question 5

Oxidation Numbers

Answer 5

System to keep track of electrons gained and lost during oxidation-reduction reactions

Question 6

Elemental form ON

Answer 6

always 0

Each H in H2 molecule has ON of 0 etc

Question 7

Monatomic ion

Answer 7

ON equals the charge on the ion

S2- has ON of -2 etc

Alkali metal ions (group 1A) always have ON +1 b/c of charge 1+

Alkaline earth metals (2A) are +2

Alumium (3A) is +3

Question 8

Nonmetals

Answer 8

Usually negative, but sometimes positive

A)ON of oxygen is usually -2 in ionic and molecular compounds, ON is -1 when it is in peroxides O2(2-)

B)ON of hydrogen is +1 when bonded to nonmetals, -1 when bonded with metals

C)Fluorine has ON of -1 in all compounds, other halogens have ON of -1 in most binary compounds and positive ON when bonded to oxygen

Question 9

Sum of ON

Answer 9

Sum is equal to 0 in neutral compound

Sum in a polyatomic ion equals the charge of the ion