Topic 14

Question 1

What is the procedure to set up an electrochemical cell

Answer 1

Clean metals with sandpaper to remove impurities
Wash metal surface with propanone
Place each element into a solution containing the ion of the same metal
Make the salt bridge from filter paper soaked in KNO3 and link each 2 beakers
Connect the electrodes with wires, crocodile clips and a voltmeter

Question 2

Why is platinum a good electrode

Answer 2

Electrically conductive and inert

Question 3

What happens to the electrode(half cell) when it has been reduced in a redox reaction

Answer 3

Reduction means the half cell has gained electrons so the electrode will get thicker

Question 4

What is the salt bridge and it’s purpose

Answer 4

Salt bridge is filter paper with saturated KNO3 solution.
Completes the circuit
Allows ions to flow through which balances the charges

Question 5

What is the voltage of the Standard hydrogen electrode

Answer 5

0V

Question 6

What happens to a half cell when it has been oxidised in a redox reaction

Answer 6

The electrode will become thinner when more of the metal ion is produced

Question 7

What are the standard conditions for the standard hydrogen electrode

Answer 7

Temperature at 298K
Pressure at 100Kpa
Concentrations of ions at 1mol/dm³

Question 8

What affects the potential value of a half cell

Answer 8

Temperature
Concentration
Pressure

Question 9

If a reaction is feasible is the E cell value positive or negative

Answer 9

Positive