Electrochemical

Question 1

Hydrogen electrode conditions

Answer 1

1 mol dm-3
100kPa
298K

Question 2

Examples of non rechargeable cells

Answer 2

Zinc/copper

Zinc/carbon

Question 3

Zinc/copper cell

Answer 3

Non rechargeable
Emf of 1.1V
Developed by John Daniel and used for telegraphs.
Impractical for portal devices due to liquid.

Question 4

Zinc/carbon cell info

Answer 4

Electrodes don’t have to be metal.
Leclanche used carbon as positive electrode (acts as inert platinum in hydrogen electrode)
Electrolyte is a paste
Commercial type uses ammonium chloride with a carbon rod, water is the electrolyte

Question 5

Disadvantage of zinc carbon cell

Answer 5

As the cell discharges, the zinc is used up and the walls of the canister become thin and prone to leakage.
The AlCl3 electrolyte is acidic and can be corrosive

Question 6

Reaction between potassium manganate and ethanedioate

Answer 6

2MnO4 - (aq) + 16H+ (aq) + 5C2O4 2- (aq) —> 2Mn 2+ (aq) + 10CO2 (g) + 8H2O (l)

Question 7

What is the function on the platinum electrode

Answer 7

Acts as a catalyst