Electrolysis Concepts and Applications

The video tutorial explains electrolysis, a process using electricity to cause chemical reactions. It covers the setup with electrodes and electrolytes, and details the reactions at the cathode and anode. Examples include sodium chloride and copper sulfate solutions, highlighting rules based on reactivity. The video also discusses electrolysis of water and molten compounds, and its use in metal purification.

What is the primary purpose of using a DC power supply in electrolysis?

• To alternate the direction of current

• To increase the temperature of the solution

• To decrease the resistance in the circuit

• To ensure a constant flow of electrons

Which type of ions are attracted to the cathode during electrolysis?

• Molecules

• Neutral atoms

• Cations

• Anions

What happens to cations at the cathode?

• They gain electrons and are oxidized

• They lose electrons and are oxidized

• They lose electrons and are reduced

• They gain electrons and are reduced

According to the reactivity series, which element is more likely to be reduced at the cathode?

• Sodium

• Chlorine

• Hydrogen

• Oxygen

What is produced at the anode when a halide ion is present in the solution?

• Metal coating

• Hydrogen gas

• Oxygen gas

• Halogen gas

In the electrolysis of copper sulfate, what is deposited on the cathode?

• Copper

• Sulfur

• Oxygen

• Hydrogen

What is the main product at the anode during the electrolysis of pure water?

• Hydrogen gas

• Oxygen gas

• Chlorine gas

• Sodium hydroxide

What is the role of cryolite in the electrolysis of aluminium oxide?

• To increase the melting point

• To decrease the melting point

• To provide additional ions

• To act as a catalyst

Why do carbon anodes need to be replaced over time in the electrolysis of aluminium oxide?

• They react with oxygen

• They dissolve in the solution

• They become coated with aluminium

• They lose conductivity

In the purification of copper, what happens to the impurities?

• They dissolve in the solution

• They form a gas

• They are deposited on the cathode

• They sink to the bottom