EXTRACTION OF ALUMINIUM GRADE 11

What is the Hall-Heroult Process used for?

• Extracting aluminum from its ore through electrolysis

• Extracting gold from its ore through electrolysis

• Extracting iron from its ore through electrolysis

• Extracting copper from its ore through electrolysis

Which substance is added to lower the melting point of alumina during the extraction of aluminium?

• Cryolite

• Sodium chloride

• Calcium carbonate

• Potassium hydroxide

What is the role of cryolite in the extraction of aluminium?

• Cryolite acts as a solvent to lower the melting point of alumina.

• Cryolite prevents the formation of aluminum oxide during extraction.

• Cryolite speeds up the chemical reaction between alumina and carbon.

• Cryolite absorbs impurities during the extraction process.

In the Hall-Heroult Process, what is the purpose of the electrolysis step?

• To extract aluminum from alumina

• To extract gold from gold ore

• To refine iron from iron ore

• To produce copper from copper sulfate

What is the chemical formula of cryolite?

• NaAlF4

• Na3AlF5

• Na3AlF6

• Na2AlF6

Why is cryolite used instead of pure alumina in the extraction of aluminium?

• To lower the melting point of the mixture

• To reduce the cost of production

• To speed up the extraction process

• To increase the purity of the final product

What type of reaction occurs during the electrolysis of alumina in the Hall-Heroult Process?

• Redox reaction

• Combustion reaction

• Neutralization reaction

• Decomposition reaction

What is the source of the aluminium ions in the electrolyte during the extraction process?

• Aluminum sulfate

• Aluminum chloride

• Aluminum hydroxide

• Alumina (Al2O3)

What is the function of the carbon anodes in the Hall-Heroult Process?

• Produce oxygen gas as a byproduct

• Absorb excess heat during the process

• Act as a catalyst for the reaction

• Conduct electricity and provide a source of carbon for the reduction of alumina to aluminum

How is the purity of the extracted aluminium ensured in the final step of the process?

• Filtration

• Distillation

• Crystallization

• Electrolysis