Oxidation - Reduction Reactions

Question 1

oxidation

Answer 1

loss of electrons

Question 2

reduction

Answer 2

gain in electrons

Question 3

Oxidising agent

Answer 3

accepts electrons and gets reduced

Question 4

Reducing agent

Answer 4

donates electrons and gets oxidised

Question 5

Identifying Redox Reactions

Answer 5

determine whether or not it is even an oxidation-reduction reaction
requires species that exhibit a change in oxidation states during the reaction

Question 6

balance redox equations

Answer 6

elements
H2O
H+
e-

Question 7

Rusting

Answer 7

corrosion of iron
most common corrosion of metal
oxygen and water must be present
redox reaction whereby oxygen acts as the oxidising agent and iron acts as the reducing agent

Question 8

Rusting

Answer 8

surface of iron at the middle of the water droplet serves as the anode, the electrode at which oxidation occurs. The iron atoms here lose electrons to form iron(II) ions.
The electrons flow to the edge of the water droplet, where there is plenty of dissolved oxygen. The iron surface there serves as the cathode, the electrode at which reduction occurs.
Oxygen gains the electrons and is reduced to hydroxide ions.
The iron(II) ions produced combine with the hydroxide ions to form iron(II) hydroxide.

Question 9

Rusting equations

Answer 9

O2 + 2H2O + 4e = 4OH-
Fe2+ 2OH- = Fe(OH)2
anode: 2Fe = 2Fe2+
cathode: O2 + 2H2O = 4OH-
overall: 2Fe + O2 + 2H2O = 2Fe(OH)2

Question 10

Common oxidising agent

Answer 10

H2SO4
KMnO4
K2Cr2O7
MnO2
Cl2
H2O2

Question 11

Common reducing agents

Answer 11

H2
Zn
C
CO
LiAlH4
NaBH4