Redox

Question 1

Oxidation numbers are like

Answer 1

Like the charge of an atom in a molecule/compound which is quoted per atom

Question 2

Rules for reassigning oxidation numbers and “hierarchy”:

Answer 2

Elemental=0
Group 1-3 = positive group number 
F=-1
Hydrogen=+1
Oxygen=-2
Then group seven=-1
Group six =-2
Group 5=-3
Then everyone else

Question 3

Roman numerals refer to what is in front of the number but not “ates” or “ites”
Sodium chlorite (VII) - what has the oxidation number of 7?
Iron (III) chloride

Answer 3

Chlorine

Iron

Question 4

OILRIG and relate to oxidation numbers

Answer 4

Oxidation is loss Reduction is gain
Oxidation = number becomes more positive
Reduction = number becomes more negative

Question 5

What is disproportionation?

Answer 5

When an element in a singly species is both oxidised and reduced in a single reaction.

Question 6

Oxidising agent

Answer 6

Causes another substance to be oxidised - it itself is reduced

Question 7

Reducing agent def

Answer 7

Causes another substance to be reduced - it itself is oxidised

Question 8

Generally metals are —— agents

Answer 8

Reducing because they like to lose electrons

Question 9

Generally non - metals are —— agents

Answer 9

Oxidising agents because they like to gain electrons

Question 10

How do you combine ionic half equations?

Answer 10

By multiplying to make the number of electrons the same then adding whatever is in the right to the right of the final equation and whatever is on the left to the left of the final equation

Question 11

Make an ionic equation under acidic conditions

Answer 11

Balance oxidation number with electrons
Balance excess oxygen with H2O on the other side
Balance with H+ on non-H2O side
Check the charges balance

Question 12

Form an ionic equation under alkaline conditions

Answer 12

Balance oxidation number with electrons
Match excess oxygen with H2O on the same side
Balance with OH- on opposite side to H2O
Check the charges balance