Redox

Question 1

oxidation vs reduction (4)

Answer 1

gain o2 vs lose o2
lose h2 vs gain h2
lose es vs gain es
increase o.s. vs decrease o.s.

Question 2

oxidation state (4)

Answer 2

1. Group 1, 2, aluminium = +1, +2, +3
2. Fluorine = ALWAYS ‒1
3. Oxygen = ‒2 UNLESS w/ F (+2) OR in peroxide (‒1) [compounds w/ O2]
4. Hydrogen = +1 UNLESS w/ metal (‒1)

Question 3

list all common oxidising agents (4)

Answer 3

O2, conc. sulfuric acid [H2SO4], acidified potassium manganate (vii) [KMnO4], acidified potassium dichromate (vi) [K2Cr2O7]

Question 4

list all common reducing agents (5)

Answer 4

H2, C, CO, SO2, aqueous potassium iodide [KI]

Question 5

list colour change for potassium manganate (vii) [KMnO4]

Answer 5

purple to colourless

Question 6

list colour change for potassium iodide [KI]

Answer 6

colourless to brown