Redox Reactions

Question 1

What is oxidation?

Answer 1

Gain of oxygen

Loss of electrons

Question 2

What is reduction?

Answer 2

Loss of oxygen
Gain of hydrogen
Gain of electrons

Question 3

What is the oxidation number?

Answer 3

The charge an atom would have if it was composed of ions

Question 4

What are the rules for oxidation numbers in compounds?

Answer 4

Overall charge is 0

Sum of oxidation numbers must equal 0

Question 5

What are the rules for oxidation numbers in molecular ions?

Answer 5

Sum of the oxidation numbers must equal the overall charge on the ion

Question 6

What is the oxidation number for an uncombined element?

Answer 6

0

Question 7

What is the oxidation number for combine oxygen?

Answer 7

-2

Question 8

What is the oxidation number for combined oxygen in peroxide’s?

Answer 8

-1

Question 9

What is the oxidation number for combined hydrogen?

Answer 9

+1

Question 10

What is the oxidation number for combined hydrogen in metal hydrides?

Answer 10

-1

Question 11

What is the oxidation number for a simple ion?

Answer 11

The charge on the ion

Question 12

What is the oxidation number for combined fluoride?

Answer 12

-1

Question 13

What is a redox reaction?

Answer 13

Where both oxidation and reduction occur within a reaction

Question 14

What happens in oxidation or reduction in terms of oxidation number?

Answer 14

Oxidation - increase in oxidation number

Reduction - decrease in oxidation number

Question 15

What happens when metals react with acids in terms of redox?

Answer 15

Metal is oxidised

Hydrogen is reduced (forms hydrogen gas)

Question 16

What are the steps for balancing a redox equation?

Answer 16

1. Write out the oxidation numbers
2. Separate the half equations
3. Balance these equations with electrons
4. Balance the redox process
5. Balance remaining atoms by adding H+ or H2O