Redox reactions

Question 1

What is oxidation?

Answer 1

Loss of electrons

Question 2

What is reduction?

Answer 2

Gain of electron

Question 3

What is a redox reaction?

Answer 3

When both reduction and oxidation take place

Question 4

What is an oxidising agent?

Answer 4

Oxidises something else whilst becoming reduced itself

Question 5

What is a reducing agent?

Answer 5

Reduces something else whilst becoming oxidised itself

Question 6

What is the best oxidising agent and why?

Answer 6

F₂

It is a smaller atom so the nucleus can pull electrons better, also very electronegative

Question 7

What is the best reducing agent and why?

Answer 7

I-

Negatively charged, larger atom so less attraction to nucleus, electrons more easily lost

Question 8

What is an oxidation state?

Answer 8

Tells you how many electrons the atom has lost or gained

Question 9

What is the oxidation state of an uncombined element?

Answer 9

0

Question 10

What is the general oxidation state of oxygen in a compound?

Answer 10

-2

Question 11

What is the oxidation state of oxygen when in a peroxide?

Answer 11

-1

Question 12

What is the oxidation state of hydrogen in a compound?

Answer 12

+1

Question 13

Wha tis the oxidation state of hydrogen in a compound with a metal?

Answer 13

-1

Question 14

What is the oxidation state of fluorine in a compound?

Answer 14

-1

Question 15

In a compound ion, what has the negative oxidation state?

Answer 15

The most electronegative element

Question 16

What do ionic half equations show?

Answer 16

Reduction or oxidation

Question 17

What are the steps to working out an overall half equation?

Answer 17

1) Work out the separate oxidation and reduction equations
2) Add water if needed
3) add electrons if needed
4) add hydrogen if needed
5) multiply any half-equations if needed so electrons are equal
6) Combine equations