batteries and fuel cells

Question 1

What are the 2 half equations for lithium ion:

Answer 1

Li + e- -> Li+

Li+ + CoO2 + e- -> Li+[CoO2]-

forms lithium cobalt oxide

Question 2

One type of lithium ion is made up from…

Answer 2

graphite electrode

lithium cobalt oxide electrode

Question 3

How are batteries recharged?

Answer 3

By making electrons flow in the opposite directions around the circuit, reversing the reaction.

Question 4

What is special about a fuel cell?

Answer 4

Chemicals are stored separately outside the cell, and are FED INTO the cell when electricity is needed.

Question 5

For the alkaline hydrogen oxygen fuel cell

what is the reaction at the negative electrode?

Answer 5

2H2 + 4OH- -> 4H2O + 4e-

g) (aq) (l

Question 6

For the alkaline hydrogen oxygen fuel cell

what is the reaction at the positive electrode?

Answer 6

O2 + 2H2O +4e- -> 4OH-

g) (l) (aq

Question 7

What is the flow of electrons in an “alkaline hydrogen oxygen fuel cell” ?

what is the flow of OH- ions in an “alkaline hydrogen oxygen fuel cell” ?

Answer 7

Electrons flow from the negative electrode through a wire , to the positive electrode

OH- ions pass through the anion exchange membrane towards the negative elctrode.

Question 8

What is the purpose of the anion exchange membrane?

Answer 8

So that anions can pass through but hydrogen or oxygen gas can not.

Question 9

What is the OVERALL PURPOSE of alkaline hydrogen oxygen fuel cell?

Answer 9

Hydrogen and oxygen react to form water

2H2 + O2 -> 2H2O
g) (g) (g

Question 10

What is the main advantage of using fuel cells in cars than an internal combustion engine?

Answer 10

Fuel cells are more efficient, as they convert more available energy into kinetic energy to get the car moving.

Question 11

Disadvantage of internal combustion engine?

Answer 11

They waste a lot of energy producing heat.

Question 12

what are some more benefits of using fuel cells in cars

hint: to do with emissions

Answer 12

The only waster product is water, so no toxic chemicals to dispose off and no CO2 emissions.

Fuel cells, don’t need to be recharged, as long as enough oxygen and hydrogen gas is supplied, cell will still be able to produce electricity.

Question 13

What are some disadvantages of using fuel cells?

Answer 13

• ENERGY is needed to actually produce a supply of hydrogen and oxygen.

-

Question 14

how can the water waste product from fuel cells be used?

Answer 14

electrolysis of water can produce hydrogen and oxygen gas

• HOWEVER, a disadvantage of this, is that ELECTRICITY is required.
• and a disadvantage of this is that, electricity is generated by burning fossil fuels.
• entire process isn’t carbon neutral.

Question 15

What is something to be aware of whilst handling hydrogen gas?

Answer 15

It is HIGHLY FLAMMABLE

• needs to be handled carefully when stored or transported.