Electrochemistry

Question 1

Anode?

Answer 1

The electrode where oxidation takes place.

Question 2

Cathode?

Answer 2

The electrode where reduction takes place.

Question 3

Electrolyte?

Answer 3

A substance that can conduct electricity by forming free ions when molten or dissolved in solution.

Question 4

Electrolysis?

Answer 4

A decomposition reaction that requires a continuous flow of electricity.

Question 5

Electrolytic Cell?

Answer 5

The apparatus where electrolysis takes place.

Question 6

Galvanic Cell? What is the polarity of the electrodes?

Answer 6

A cell that contains a spontaneous, exothermic reaction that converts chemical potential energy into electrical energy. Cathode is (+) and Anode is (-).

Question 7

What does a galvanic cell consist of?

Answer 7

Two half cell containers, an electrode in each half cell (anode and cathode), an electrolyte in each half cell container and a salt bridge.

Question 8

Electrolytic Cell? What are electrode polarities?

Answer 8

A non-spontaneous, endothermic reaction that converts electrical energy into chemical energy. Cathode is (-) and Anode is (+).

Question 9

What does an electrolytic cell consist of?

Answer 9

One container for the reaction to take place, two electrodes (cathode and anode), the electrolyte solution and a battery.

Question 10

Conditions for half cell potentials.

Answer 10

Concentration: 1 mol•dm-3
Temperature: 298K (25°C)
Pressure (gases only): 101.3 kPa (1atm)
Pt (Platinum) electrodes are used for all half cells that don’t involve a metal.

Question 11

Function of Pt Electrode?

Answer 11

It provides a surface for oxidation or reduction to take place on. For gasses that is.

Question 12

The factors affecting electrode potential values?

Answer 12

Concentration of reacting ions, temperature of electrolytes, pressure for gasses and the composition of the half cells.

Question 13

What is the difference between inert and active electrodes?

Answer 13

Inert: doesn’t interfere with the reactions. Provides point of electrical connection.
Active: takes part in recations usually showing decrease/increase in mass. Also provides a point of electrical connection.

Question 14

Electroplating?

Answer 14

Process using electrolysis in which a thin layer of a desired metal is plated (coated) onto another object.

Question 15

What are the 3 cells that are used in the chlor-alkali industry?

Answer 15

The Mercury Cell.
The Diaphragm Cell.
The Membrane Cell.

Question 16

What is the function of the salt bridge for a galvanic cell and what is it responsible for?

Answer 16

The salt bridge completes the circuit, allowing charge to flow while maintaining electrical neutrality. It is responsible for the internal resistance of the cell.