Redox reactions

Question 1

Oxidising agent

Answer 1

1. accepts electrons from another reagent
2. is reduced

Question 2

Reducing agent

Answer 2

1. gives electrons to another reagent
2. is oxidised

Question 3

Draw an electrochemical cell

Answer 3

1. salt bridge
2. high resistance voltmeter
3. metal electrodes
4. aqueous solution (1moldm^-3)
5. standard conditions 298K, 100KPa

Question 4

Negative standard electrode potential

Answer 4

1. produces more electrons
2. oxidised
3. stronger reducing agent
4. equilibrium shifts to the left

Question 5

Standard electrode potential

Answer 5

1. the potential difference of a cell
2. when the electrode is connected to the standard hydrogen electrode
3. under standard conditions

Question 6

Draw the standard hydrogen electrode

Question 7

Cell voltage formula

Answer 7

right E- left E

Question 8

Affect of concentration on electrode potential

Answer 8

1. equilibrium will shift to counteract the change
2. changes concentration of electrons

Question 9

Feasibility of reaction

Answer 9

1. must have positive cell potential
2. rate of reaction has no effect

Question 10

Lithium half cell battery advantage

Answer 10

1. low density
2. high reactivity
3. high electrode potential

Question 11

Lithium half cell battery disadvantage

Answer 11

1. toxic
2. fire risk- high reactivity

Question 12

Fuel cell

Answer 12

1. energy from reaction of fuel with oxyegn
2. fuel- hydrocarbon, hydrogen or alcohol
3. creates a voltage
4. acidic or alkaline solution

Question 13

Advantage of fuel cell

Answer 13

1. greater efficiency
2. only H2O formed- not polluting

Question 14

Disadvantage of fuel cell

Answer 14

1. H2 difficult to store
2. H2 difficult to manufacture initially

Question 15

Positive standard electrode potential

Answer 15

1. gains electrons
2. reduced
3. stronger oxidising agent
4. equilibrium shifts to the right