Redox reactions

Question 1

state what is means by the term REDOX reaction.

Answer 1

A reaction in which the oxidation states of all the oxidising agents change.

Question 2

Which type of reactions are not redox reactions, and explain why.

Answer 2

1. Atoms with the same elctronegativity.
2. Acid-base reactions are not redox, this is because the oxidation states, dont change
3. Double displacement reactions, this is because the oxidation states havent changed.

Question 3

What is one thing you need to be really carefull when asked, “what is the oxidising agent”

Answer 3

Make sure you say the entire reactant.

Question 4

What is oxidation?

Answer 4

When something gains electrons in a reaction, we call it the oxidising agent.

When an elements oxidation state, increases, we say it has been oxidised.

Question 5

What is reduction?

Answer 5

When something loses electrons, we say it is the reducing agent.

When an elements oxidation state, decreases, we say it has been reduced.

Question 6

how many oxidation state rules, are there?

Answer 6

9 total rules.

Question 7

what is rule number 1

Answer 7

Uncombined elements have an oxidation state of 0.

Question 8

what is rule number 2

Answer 8

in a monoatomic ion, its oxidation state is equal to its charge.

Question 9

what is rule number 3

Answer 9

for compounds, the sum of the oxidation states, is equal to the overall charge of the compound.

Question 10

what is rule number 4

Answer 10

group 1 atoms in a compound, always have and oxidation state of +1.

Question 11

what is rule number 5

Answer 11

group 2 atoms in a compound, always have the oxidation state +2.

Question 12

what is rule number 6

Answer 12

Flourine in a compound, always has the oxidation state -1.

Question 13

what is rule number 7

Answer 13

hydrogen in a compound, always has the oxidation state of +1.

Question 14

What is rule number 8?

Answer 14

oxygen in a compound, has an oxidation state of -2.

Question 15

What is rule number 9?

Answer 15

Chlorine in a compound, has an oxidation state of -1.

Question 16

What do we do when there is a conflict between rules?

Answer 16

we ALWAYS choose the one that comes first.

Question 17

What is a disproportionation reaction?

Answer 17

A reaction in which an element is both oxidised, and reduced in the same reaction, is called a disproportionation reaction.

Question 18

How do we create half-equations?

Answer 18

step 1: We identify the oxidising/ reducing agent.
Step 2: balance the atoms.
step 3: balance the charges, by adding electrons.

(LOOK ON GOODNOTES 5 FOR CLARIFICATION).

Question 19

How do we combine the half equations?

Answer 19

1. Multiply the half equations, so that the newly added electrons, cancel each other out.
2. combine the half equations.

Question 20

how do we create half equations, in aqueous, acidified solutions?

Answer 20

Step 1: Identify the oxidising/reducing agent.
step 2:
A: Balance the atoms.
B: Balance the oxygens, by adding H2O.
C: Then balance the hydrogen atoms, by adding H+ ions.
Step 3: Balance the charges.