Unit test

What does the term electrolysis mean? (Hint: Electro + Lysis)

Define Oxidization

• Oxidization is the gain of electrons

• Oxidization is the melting of compounds

• Oxidization is the loss of electrons

• Oxidization is gain of water molecules

The pH Scale measures:

• Positive or negative ions

• Acids and Bases

• Electricity

• None of These

What are the rods made of in Electrolysis?

Why can ionic compounds not conduct electricity when they are solid?

• their electrons are not free to move
• their ions are free to move
• their ions are not free to move
• their electrons are free to move

During the electrolysis of molten calcium bromide, what will be produced at the cathode and the anode?

• Cathode - calcium metal

• Cathode - hydrogen gas

• Anode - oxygen gas

• Anode - bromine gas

Look at the equation: X⁺ + e^- → X. Is this oxidation or reduction?

• Oxidation

• Reduction

What type of bonding is present in compounds that can be electrolysed?

• Covalent

• Ionic

• Metallic

• Hydrogenic

The picture shows electrolysis of copper (II) sulphate solution using graphite electrodes. Besides formation of brown solid on the cathode, what other observations can be made?

• The mass of anode decreases.

• The blue colour of the solution fades.

• The blue colour of the solution remains same.

• The blue colour solution becomes darker.

Choose the half-equation that shows the discharge of aluminium ion.

• Al³⁺ - 3e^- --> Al

• Al²⁺ + 3e^- --> Al

• Al³⁺ + 3e^- --> Al

• Al³⁺ --> Al + 3e^-