Faraday's Laws and Uses of Electrolysis

Which of the following corresponds to the first law of electrolysis?

• m = zIt

• n = Q/F

• 1F = 96500C

The extraction of aluminium involves the electrolysis of purified bauxite dissolved in molten cryolite, Na₃AlF₆. What is the main purpose of the cryolite?

• to reduce the melting point of the mixture

• to provide an additional source of aluminium

• to increase the electrical conductivity of the melt

• to prevent the re-oxidation of the aluminium formed at the cathode

Diagram shows the application of of electrolysis in...

• Extraction of metals

• Purification of metals

• Electroplating of metals

• Wastewater treatment using Electrocoagulation

What is the purpose of using electrolysis in the extraction of metals?

• To increase the melting point of the metal

• To decrease the electrical conductivity of the metal

• To purify the metal

• To increase the chemical reactivity of the metal

What is the main advantage of electroplating of metals?

• To prevent corrosion

• To increase the weight of the metal

• To decrease the electrical conductivity of the metal

• To reduce the melting point of the metal

1. A steady current of 4 amperes is passed through aqueous copper (II) sulphate solution for 1800 seconds using platinum electrodes. Calculate the mass of copper deposited. (Cu = 63.5 g/mol, 1F = 96500C)

• 2. 2.4 g

• 4.8 g

• 1.7 g

• 5.8 g

Zinc-Plated Iron is also known as

• Iron ore

• Galvanized Iron

• Soft iron

• Hard Iron

What is the unit of electric charge in Faraday's laws?

• Joule

• Coulomb

• Ampere

• Ohm

If a current of 2.5 A is passed through a solution for 3 hours, calculate the charge passed.

• 75,000 C

• 30,000 C

• 40,000 C

• 27,000 C

What is Faraday's first law of electrolysis?

• The amount of substance deposited is directly proportional to the current

• The amount of substance deposited is inversely proportional to the current.

• The amount of substance deposited is proportional to the voltage.

• The amount of substance deposited is constant.