The video explains the extraction of aluminum, the most abundant metal on Earth, which is costly due to high electricity usage. Aluminum is extracted from bauxite ore through electrolysis. The process involves dissolving aluminum oxide in molten cryolite to lower its melting point. Electrolysis occurs with graphite electrodes, where aluminum forms at the cathode and oxygen at the anode, reacting with carbon to form carbon dioxide. This reaction wears away the anode, adding to the cost. The video details the reactions at the electrodes and emphasizes the high electricity demand for aluminum extraction.

What is the primary reason aluminum is expensive to extract?

• It has a high density.

• It corrodes easily.

• It requires a lot of electricity.

• It is rare on Earth.

Why is aluminum oxide dissolved in cryolite during the extraction process?

• To lower its melting point.

• To increase its density.

• To change its color.

• To make it more reactive.

What material is used to coat the steel case in the electrolysis process?

• Copper

• Graphite

• Iron

• Zinc

What happens to the oxygen ions at the positive anode during electrolysis?

• They are absorbed and form carbon monoxide.

• They are neutralized and form oxygen gas.

• They are reduced and form water.

• They are oxidized and form carbon dioxide.

Why does the anode need to be replaced regularly in the electrolysis process?

• It corrodes due to water.

• It melts due to high temperature.

• It wears away due to reaction with oxygen.

• It dissolves in cryolite.