Oxidation Reduction Redox

Question 1

What is an advantage of oxidation states over charges?

Answer 1

They can also be applied to covalent compounds

Question 2

What is the first rule for calculating oxidation states?

Answer 2

Uncombined elements or elements only bonded to other elements of the same type for example, oxygen have an oxidation state of zero

Question 3

What is the second rule of calculating oxidation states?

Answer 3

In a compound, the sum of oxidation states of all elements within it is 0

Question 4

What’s the third rule of calculating oxidation states?

Answer 4

In a complex ion, the sum of oxidation states of all elements is equal to the charge on the ion (compound ion)

Question 5

What is the fourth rule of calculating oxidation states?

Answer 5

Oxidation state of group one metals in a compound is always +1

Question 6

What is the fifth rule of calculating oxidation states?

Answer 6

Oxidation state of group 2 metals in a compound is always +2

Question 7

What is the sixth rule of calculating oxidation state?

Answer 7

Oxidation state of aluminium in a compound as always +3

Question 8

What is the seventh rule of calculating oxidation state?

Answer 8

Oxidation state of hydrogen in a compound is plus one except in a metal hydrate where it is minus one

Question 9

What is the eighth rule of calculating oxidation states?

Answer 9

Oxidation state of oxygen in a compound is always-2 except in a peroxide where its -2

Question 10

Describe the steps for writing half equations

Answer 10

1. Balance the species with the variable oxidation state.
2. Balance oxygen through addition of water.
3. Balance hydrogen through addition of hydrogen ions.
4. Balance charge by adding electrons.

Question 11

Define oxidation

Answer 11

A reaction in which an atom or group of atoms loses electrons

Question 12

Define reducing agent

Answer 12

An electron donor (reduces another species)

Question 13

Define reduction

Answer 13

Reaction in which an atom or group of atoms gains electrons

Question 14

Define oxidising agent

Answer 14

An electron receptor (oxidises another species)

Question 15

What does oil rig stand for?

Answer 15

Oxidation is loss of electrons or hydrogen
Reduction is gaining of electrons or hydrogen

Question 16

How do you know if something is oxidation?

Answer 16

If oxidation state increases its oxidation

Question 17

How do you know if something is reduction?

Answer 17

If oxidation state decreases its reduction

Question 18

What are the rules for combining half equations?

Answer 18

1. One half equation must show oxidation (electrons added on the right hand side) and one must show reduction (electrons added on the left-hand side).
2. Before you combine them the number of electrons in each half equation must be equal (multiply them up to lowest common denominator.)
3. Add equations together all reactants and products from both equations included.
4. Remove spectator ions/electrons.

Question 19

How do you know if something is the oxidising or reducing agent?

Answer 19

Oxidising agent is what’s reduced
Reducing agent is what oxidised