Skip navigation

Evaluation

Attempt all the questions.

Multi-choice

Question

1. Metals are extracted from _____

Answers

A. Rocks

B. Minerals

C. Ores

D. Vitamins

Feedback

Question

2. Carbon reduction involves reduction by _____.

Answers

Carbon monoxide

Zinc

Carbon dioxide

Coke

Feedback

Question

3. The name of the substance used to lower the melting point of Aluminium oxide ore in the electrolytic extraction of Aluminium is called

Answers

Cryolite

Carbon

Bauxite

Haematite

Feedback

Question

4. During the electrolysis of molten Aluminium oxide ore, the Aluminium ions move? 

Answers

To the positive electrode because they are negatively charged.

To the positive electrode because they are positively charged.

To the negative electrode because they are positively charged.

 To the negative electrode because they are negatively charged.

Feedback

Cloze Activity

Read the paragraph below and fill in the missing words.

The process of extracting metal ores buried deep underground is called . 

Aluminium ore is called   (Al2O3). The bauxite is purifiedto yield a white powder  Aluminium oxide (also known as alumina) from which Aluminium can be extracted.

The extraction is done by  , but first the Aluminium oxide must be melted so that electricity can pass through it. However, Aluminium oxide has a very melting point (over 2,000°C) so it would be expensive to melt it.

Instead, it is dissolved in molten  an Aluminium compound with a lower melting point than Aluminium oxide. The use of molten cryolite as a solvent reduces some of the energy costs involved in extracting Aluminium by allowing the ions in Aluminium oxide to move freely at a lower temperature.

Enable JavaScript