5.4 electrode potentials

Question 1

define: standard electrode potential

Answer 1

The e.m.f. of a half-cell compared with a hydrogen halfcell
298K
1 mol dm-3
100kPa

Question 2

is a negative metal electrode reduced or oxidised in a cell?

Answer 2

oxidised

Question 3

why is a salt bridge used in an electrochemical cell?

Answer 3

allows ions to flow

Question 4

which direction do electrons flow?

Answer 4

negative to positive

Question 5

will conc of ions increase or decrease at the negative electrode in a cell?

Answer 5

increase

Question 6

overall reaction in an alkaline hydrogen/oxygen fuel cell?

Answer 6

Question 7

is the positive metal electrode reduced or oxidised in a cell?

Answer 7

reduced

Question 8

advantage of electrochemical cells

Answer 8

1. for hydrogen cells, only waste product = water
2. more efficient than convential combustion engines
3. less pollution

Question 9

disadvantages of electrochemical cells

Answer 9

1. production of cells uses toxic chemicals
2. chemicals used are often flammable

Question 10

what do fuel cells do

Answer 10

produce energy by reacting fuel with an oxidant

Question 11

where are lithiam batteries found?

Answer 11

mobile phones