redox

Question 1

oxidisation numbers

Answer 1

Group 1 = +1
Group 2 = +2
Aluminium = +3
Fluorine = -1
Hydrogen = +1(except in metal hydrides -1)
Oxygen = -2 (except in peroxide or with F)
Chlorine = -1 (except in compounds with O or F)

Question 2

constructing full ionic equtiosn in acid

Answer 2

• balance eelemtns that aren’t oxygen or hydrogen
• add h2o to blaance oxygen
• add h+ tp balance the hydrogen
• add e- to balance charges

Question 2

constructing full ionic equtiosn in alkali

Answer 2

• write ina ciidic solution
• add oh- to both sides
• combine h and oh t both sides to make h20
• cancel out the wwaters

Question 3

combinign half equations

Answer 3

lookk at elctrons
like simultaenous euations
u know this ho

Question 4

Balancing equations using oxidation numbers

Answer 4

1. Write down the formulae for all of the species that appear in the equation.
2. Identify the changes in oxidation number.
3. Balance so that the total decrease in oxidation number on one elements is the same as the total increase of the other.
4. Balance for oxygen and hydrogen.
5. Add the state symbols if required.