1.11 Electrochemical Cells

Question 1

What is the reference for all electrochemical cells?

Answer 1

The hydrogen electrode

Question 2

Hydrogen Electrode

Answer 2

H+ +e- → 1/2 H2
Pt is surface for e- transfer
Standard conditions and states
Salt Bridge

Question 3

Why is a salt bridge used in electrochemical cells?

Answer 3

To prevent charge building up too quickly

Question 4

What is the standard notation for cells?

Answer 4

Pt (s) | H+(aq) || Cu2+(aq) | Cu

Question 5

When the electrochemical cell is positive or negative, what OILRIG?

Answer 5

Eø +ve = Reduction

Eø -ve = Oxidation

Question 6

How do you calculate the EMF of a cell?

Answer 6

EMF= Eø RHS - Eø LHS

Question 7

What are lithium ion batteries?

Answer 7

rechargeable batteries used in small devices like phones

Positive electrode:
Li+ + CoO2 + e- → Li+(CoO2)-

Negative electrode:
Li+ +e- → Li

Question 8

What are fuel cells half equation?

Answer 8

2H2 + 4OH- → 4H2O +4e-

O2 + 2H2O +4e- → 4OH-

Question 9

What are fuel cells and their advantages?

Answer 9

NaOH electrolyte, H2 and O2 are pumped in and exchange over a semi permeable barrier

Only byproduct is H2O
Very efficient *3 per g of petrol
H2 is explosive
H needs to be mined
Takes up a lot of space