Electrochemical cells

What is an electrolyte?

• The liquid part of the electrochemical cell

• The metal part of the electrochemical cell

• The part that measures the voltage in an electrochemical cell

How do you complete the circuit when using 2 half-cells?

• acid bridge

• base bridge

• salt bridge

The circuit must be complete for the electrons to flow.

• True

• False

The E⁰ value for all electrolysis reactions is

• positive

• neutral

• negative

Chlorine is produced from the electrolysis of sodium chloride solution in a diaphragm cell. What is the use of the diaphragm in the cell

• Removes impurities from sodium chloride

• Increases the rate of production of chlorine

• Prevents chlorine from escaping from the cell

• Prevents chlorine from coming into contact with sodium hydroxide

Industrially, aluminium is extracted from the electrolysis of its molten ore. However, why is more emphasis placed on recycling of aluminium than the extraction of aluminium from its ore?

• The extraction process is very difficult

• The cost of extracting aluminium from its ore is very high

• Extracting aluminium from its ore will contaminate the environment

• Extracting aluminium from its ore will cause the source to be depleted

Chromium and nickel are used in the electroplating industry. Whih of the following is/are true about electroplating?

1. The material to be plated is the anode

2. Reduction occurs at the cathode

3. The electrolyte used contains the plating metal ions

• 1

• 1 and 2

• 2 and 3

• 1, 2 and 3

Mercury and diahragm cells are used in the industrial processes for the electrolysis of brine. Which of the following is NOT the product of the two processes?

• Sodium metal

• Sodium hydroxide solution

• Chlorine gas

• Hydrogen gas

Which statement explains why graphite powder is spread onto plastic material first in plastic electroplating process?

• Graphite is an electric conductor

• Plastic becomes more resistant to heat

• Plastic electroplating process is accelerated

• Graphite can form chemical bond with plastic

What is frequently done to protect aluminium articles from subsequent corrosion?

• Aluminium is coated with an inert metal

• Cryolite is added to the aluminium ore before it is used

• Aluminium is first oxidised by air to form an inert oxide layer

• The aluminium is made the anode during electrolysis