Y13 Electrode potentials

Question 1

What are the 3 types of half cell?

Answer 1

1. Metal + its ion
2. Gas + its ion
3. Ions in 2 different oxidation states

Question 2

How would a half cell containing Cu and Cu(2+) ions be written?

Answer 2

Cu/Cu(2+)

Question 3

Why are redox reactions necessary in cells?

Answer 3

Movement of electrons

Question 4

Standard electrode potential definition

Answer 4

The e.m.f of a half cell connected to a standard hydrogen half cell under standard conditions of: 298 K, 1.00 mol dm-3, 100 kPa

Question 5

In which direction does equilibrium shift for the most positive and most negative half cell?

Answer 5

Most positive: RIGHT
Most negative: LEFT

Question 6

When given a table of electrode potentials, how do you know which species will be the best oxidising and reducing agents?

Answer 6

Oxidising agent: Most POSITIVE
Reducing agent: Most NEGATIVE

Question 7

How is E(cell) calculated?

Answer 7

E (positive electrode) - E (negative electrode)

Question 8

How do you construct the overall cell reaction equation when reacting 2 half cells?

Answer 8

Most positive shifts right, most negative shifts left. Multiply electrons to cancel them out.

Question 9

How can you tell which half cell reactions are feasible?

Answer 9

Reactions where one has a more positive E than another so positive - negative

Question 10

What are primary cells?

Answer 10

Non-rechargeable

Question 11

What are secondary cells?

Answer 11

Rechargeable

Question 12

Fuel cell definition

Answer 12

Provides a voltage from the continuous reaction of a fuel with oxygen