A2 Electrochemistry part2

Question 1

types of cells

Answer 1

rechargeable, non rechargable fuel cells

Question 2

cell advantages

Answer 2

are portable

Question 3

battery definition

Answer 3

one or more cell

Question 4

cheap cells

Answer 4

the chemicals are used up in the cell

this causes the voltage/ potential to fall to 0.00 so no electrons flow. so no electricity

Question 5

rechargeable batteries

Answer 5

the reaction is reversible when you apply an external current to regenerate the current

Question 6

fuel cell

Answer 6

fuel cells have a continous supply of chemicals so they do not get used up /or need to be applied with an external current ish

Question 7

acidic hydrogen fuel

Answer 7

h2 === > 2h+ 2e- anode negative

o2 + 4e- + 2h+======> 2h20 cathode positive

Question 8

alkali

Answer 8

h2 + oh- =====> h20 + 2e- anode negative

o2 + h20 + 4e- =======>4 oh- + vcahtode positive

Question 9

what happens to the hydrogen ions

Answer 9

the hydrogen ions move in the electrolyte from a high concentration of protons to a low concentration.

Question 10

what are oxidising agents?

Answer 10

gains electrons

Question 11

why is KCL inappropriate

Answer 11

cl- ions react to form a precipitate with a sliver

Question 12

what happens

Answer 12

Fe is oxidised to Fe 111 ions

Question 13

what happens when equilibrium shifts left

Answer 13

the electrode potential becomes more positive

Question 14

why is the emf value constant for the fuel cells

Answer 14

the reactants are constantly added in the cell so the concentration remains constant