250+ TOP MCQs on Chemical Processes of Aluminium and Answers

Aerospace Materials and Processes Multiple Choice Questions on “Chemical Processes of Aluminium”.

1. Which of the following is a chemical process used to extract aluminium?
a) Osmosis
b) Radiography
c) Heliography
d) Pyrometallurgy
Answer: d
Clarification: Aluminium is obtained through ores like bauxite. To extract aluminium several chemical methods and processes are applied. Pyrometallurgy is a chemical process that involves extracting metals in the presence of high temperatures.

2. Recycling of aluminium requires _________ of energy to make new aluminium.
a) 0.5%
b) 25%
c) 5%
d) 50%
Answer: c
Clarification: Aluminium can be absolutely recycled. In any of its forms for example tins, cans, etc. it can be taken to a plant where it is treated. In this process, only five percent of energy is required to manufacture new aluminium.

3. Hydrometallurgy is the process of extracting __________ from ___________
a) flight parts, metals
b) metals, flight parts
c) metals, ores
d) ores, metals
Answer: c
Clarification: Hydrometallurgy is a chemical process that can be used in the extraction of aluminium. It is a process that involves extracting metals from ores by preparing and using an aqueous solution in the process.

4. Aluminium can be extracted using electrometallurgy.
a) True
b) False
Answer: a
Clarification: Aluminium can be extracted using several chemical and electrical processes. Electrometallurgy is one such process that involves the extraction of aluminium by using an electrical discharge in the process.

5. Aluminium ores can be obtained in large amounts from which of the following countries?
a) Africa, Greenland
b) Africa, Australia
c) Greenland
d) Australia
Answer: b
Clarification: Aluminium is obtained through ores, typically bauxite. It is present in several countries like Greece, the United States, France, India and China. The ore bauxite is present abundantly in Africa and Australia.

6. The Hall-Heroult process is used for ___________ aluminium.
a) breaking
b) distributing
c) smelting
d) mixing
Answer: c
Clarification: The Hall-Heroult process is used in the smelting of aluminium. Smelting refers to the extraction of metal using heat. Several metals can be extracted using this process, including aluminium, silver, copper, iron, etc.

7. The Hall-Heroult process is carried out at a temperature of __________ industrially.
a) 940-980°C
b) 200-300°C
c) 10,000-50,000°C
d) 50-70°C
Answer: a
Clarification: The Hall-Heroult process is an extraction process of metals that involves the usage of heat. For this process, when it is being carried out industrially for a large quantity, the temperature at which it is done is between 940-980°C.

8. Cryolite cannot be used in the Hall-Heroult process of smelting aluminium.
a) True
b) False
Answer: b
Clarification: The above statement is incorrect. Molten cryolite is used in the Hall-Heroult process of extraction of aluminium. It is not a common mineral and is usually colourless or white. It is of brittle tenacity.

9. The Hall-Heroult process produces around _______ pure aluminium.
a) 100%
b) 20%
c) 98%
d) 4%
Answer: c
Clarification: The Hall-Heroult extraction process is extremely advantageous and effective. When the ore undergoes the heat treatment for the extraction of the desired metal, in the case of aluminium, 98% of pure aluminium can be obtained.

10. The voltage in the Hall-Heroult process is around __________
a) 2-9 V
b) 15.5-16.5 V
c) 26-45 V
d) 6-8 V
Answer: d
Clarification: The Hall-Heroult process is widely used. It involves the mixing of molten cryolite with alumina to perform electrolysis. The mixing of these results in a lower melting point of the molten bath. The voltage in this process is typically 6-8 V.