23.4 Electrode potentials

Question 1

what does a voltaic cell do?

Answer 1

converts chemical energy to electrical energy

Question 2

how do redox reactions generate electrical energy?

Answer 2

there is a transfer of electrons so electrical energy is formed

Question 3

what is a half-cell?

Answer 3

contains chemical species required for a redox reaction

Question 4

what is made when 2 half-cells are connected?

Answer 4

a voltaic cell

Question 5

what would happen if the 2 half-cells were mixed?

Answer 5

the energy created would be heat energy not electrical energy

Question 6

what are the 2 types of half-cells?

Answer 6

metal/metal ion
ion/ion

Question 7

what is a metal/metal ion half-cell?

Answer 7

a metal rod dipped into a solution of it’s aqueous metal ion

Question 8

what is the phase boundary?

Answer 8

the point where the aqueous metal ions come into contact with the metal rod

Question 9

what is created at the phase boundary in a metal/metal ion half-cell?

Answer 9

an equilibirum

Question 10

what is the forward reaction in the EQ formed?

Answer 10

reduction

Question 11

what is the backward reaction in the EQ formed?

Answer 11

oxidation

Question 12

what is an ion/ion half cell?

Answer 12

contains ions of the same element but in different oxidation states

an inert metal electrode is used to transfer electrons
(made of Pt)

Question 13

which electrode is reduced?

Answer 13

the one with the more reactive metal

Question 14

which electrode is oxidised?

Answer 14

the one with the less reactive metal

Question 15

which electrode is the negative one?

Answer 15

the one which is oxidised
loses electrons

Question 16

which electrode is the positive one?

Answer 16

the one which is reduced
gains electrons

Question 17

what is the standard electrode potential?

Answer 17

the tendency for a species to be reduced and gain electrons

Question 18

what is the standard used for standard electrode potential?

Answer 18

half-cell with H2 gas and an acid solution with a Pt electrode

Question 19

what is the standard electrode potential of a hydrogen half-cell?

Answer 19

0V

Question 20

how is standard electrode potential measured?

Answer 20

the half-cell being measured is connected to a hydrogen half-cell by a wire
they are also connected by a salt bridge which allows for ions to flow

Question 21

what is a salt bridge made out of?

Answer 21

filter paper soaked in electrolyte

Question 22

the more negative the E⊖

Answer 22

greater the tendency to lose electrons and be oxidised

Question 23

the more positive the E⊖

Answer 23

greater the tendency to

Question 24

the more negative the E⊖

Answer 24

the greater the tendency to LOSE electrons and undergo oxidation

Question 25

the more positive the E⊖

Answer 25

the greater the tendency to GAIN electrons and undergo reduction

Question 26

how is the standard cell potential calculated?

Answer 26

E⊖ (reduced) - E⊖ (oxidised)

Question 27

what are the charge carriers in the wires?

Answer 27

electrons

Question 28

what are the charge carriers in salt bridge?

Answer 28

ions