2.1.5 -Redox

Question 1

What is an oxidation number?

Answer 1

The number of electrons an atom uses to bond with any other atom.

Question 2

What is the oxidation number of an uncombined element such as C, H or O₂?

Answer 2

0

Question 3

What is the oxidation number of combined oxygen such as in H₂O?

Answer 3

-2

Question 4

What is the oxidation number of oxygen in peroxides?

Answer 4

-1

Question 5

What is the oxidation number of combined hydrogen such as in NH₃, or H₂S?

Answer 5

+1

Question 6

What is the oxidation number of combined hydrogen in metal hydride such as LiH?

Answer 6

-1

Question 7

What is the oxidation number of a simple ion?

Answer 7

The charge of the ion

Question 8

What is the oxidation number of combined flourine such as in NaF, or CaF₂?

Answer 8

-1

Question 9

When an element has more than one stable oxidation number, how is it indicated?

Answer 9

As a Roman numeral

Question 10

What is the oxidation number of Fe in iron (III) chloride?

Answer 10

+3

Question 11

What are oxyanions?

Answer 11

Negative ions that have an element along with oxygen.

Question 12

What is the oxidation number of S in SO₄^2-?

Answer 12

+6

Question 13

Define oxidation in terms of electron transfer and oxidation number.

Answer 13

Oxidation is

• Loss of electrons
• an increase in oxidation number

Question 14

Define reduction in terms of electron transfer and oxidation number.

Answer 14

Reduction is

• Gain of electrons
• A decrease in oxidation number

Question 15

What is a redox reaction?

Answer 15

A reaction in which both oxidation and reduction takes place.

Question 16

What is the oxidation number of a single metal atom?

Answer 16

0