3.1.7 Redox

Question 1

What is the name for a reaction where a species is both oxidised and reduced?

Answer 1

Disproportionation

Question 2

What are the oxidation state rules of different elements?

think: group 1, group 2, halogens, hydrogen, oxygen

Answer 2

Group 1 = +1
Group 2 = +2
Fluorine = -1
Oxygen = -2 (except peroxides where it is -1 and oxygen fluoride where it is +2)
Hydrogen = +1 (except metal hydrides where it is -1)

Question 3

What are the oxidation state rules of compounds?

Question 4

What is the half-equation for the reduction of Mn(VII) to Mn(II) ions in acidified solution?

Answer 4

MnO4^- + 8H+ + 5e- → Mn^2+ + 4H2O

Question 5

Show the stages of titanium extraction from TiO2.
State what happens in the equation involving magnesium.

Answer 5

TiO2 + 2Cl2 + 2C → TiCl4 + 2CO

TiCl4 + 2Mg → Ti + 2MgCl2
(TiCl4 reduced)

Question 6

What is the oxidation state of hydrogen and oxygen in hydrogen peroxide?

Answer 6

H = +1
O = -1