Redox

Question 1

4 definitions of oxidation

Answer 1

Gain in oxygen
Loss of hydrogen
Loss of electrons
Increase in oxidation state

Question 2

4 definitions of reduction

Answer 2

Loss of oxygen
Gain in hydrogen
Gain in electrons
Decrease in oxidation state

Question 3

What reactions aren’t redox reactions?

Answer 3

Neutralisation
Precipitation
Decomposition of metal carbonates

Question 4

Oxidising agent

Answer 4

A substance that causes another substance to be oxidised

Question 5

Reducing agent

Answer 5

A substance that causes another substance to be reduced

Question 6

Test for oxidising agent

Answer 6

Add aqueous potassium iodide.
In the presence of oxidising agents, iodide ions will be oxidised to be iodine.
Colour change from colourless to brown.

Question 7

Test for reducing agent

Answer 7

Add acidified aqueous potassium manganate (VII).
In the presence of reducing agents, manganate ions are reduced to be manganese (II) ions.
Colour change from purple to colourless.

Question 8

Common oxidising agents

Answer 8

Oxygen
Halogens (Chlorine, bromine)
Acids (Conc. sulfuric acid, nitric acid)
Potassium manganate (VII) KMnO4
Potassium dichromate (VI) K2Cr2O7

Question 9

Common reducing agents

Answer 9

Carbon, carbon monoxide
Hydrogen, hydrogen sulfide
Potassium iodide, sulfur dioxide
Metals
Ammonia

Question 10

Are group I metals reducing/oxidising agents?

Answer 10

Reducing agents

Question 11

Are group VI metals reducing/oxidising agents?

Answer 11

Oxidising agents