Redox

Question 1

What is the oxidation number of any element?

Answer 1

0

Question 2

What is the oxidation number of an ion?

Answer 2

The same as the charge of the ion

Cl- = -1

Question 3

What does the sum of the oxidation numbers in a molecule have to equal?

Answer 3

0

Question 4

What is Fluorine’s oxidation number?

Answer 4

-1 (ALWAYS)

Question 5

What is Oxygen’s oxidation number?

Answer 5

-2 (Normally)
-1 (in peroxide)
+2 (combined with fluorine)

Question 6

What is Hydrogen’s oxidation number?

Answer 6

+1 (apart from in metal hydrides)

Question 7

Are metals positive or negative?

Answer 7

Always positive

Question 8

What is reduction?

Answer 8

When the oxidation number of an element decreases

Question 9

What is oxidation?

Answer 9

When the oxidation number of an element increases

Question 10

What are half equations?

Answer 10

An equation split into 2, showing which elements are oxidised and which are reduced?

Question 11

Split this equation into 2 half equations

Zn(s) + 2Ag+(aq) -> Zn^2+(aq) + 2Ag(s)

Answer 11

Zn(s) -> Zn^2+ + 2e-

2Ag+(aq) + 2e- -> 2Ag(s)

Question 12

What is Chlorine’s oxidation number?

Answer 12

-1 (almost always)

Question 13

What do you call the ion that has an oxidation number that doesn’t change?

Answer 13

Spectator ion

Question 14

What is a redox reaction?

Answer 14

One where oxidation and reduction occurs

Question 15

What is a disproportionation?

Answer 15

When the same element has been both oxidised and reduced