Grade 10 Review - Electrolysis & Chemical energetics

Key words: The breakdown of an ionic compound, molten or in aqueous solution, by the use of electricity.

(a)  

When copper(II) sulfate solution is electrolyzed, which substance is formed at the cathode?

• copper

• sulfur

• hydrogen

• oxygen

Bauxite is an ore containing aluminium oxide. What are the products of electrolysis of molten bauxite?

• aluminium

• oxygen

• hydrogen

• chlorine

Identify the components of the following electroplating diagram.

a

b

c

d

Anode

Cathode

Battery

Silver Nitrate Solution

Organize these processes/reactions into the right categories.

Groups:

(a) Physical changes

,

(b) Chemical changes

• Photosynthesis in plants
• Evaporation of sea water

• Breaking of glass
• Melting of ice

• Chopping of wood
• Burning of wood
• Fermentation of sugar
• Rusting of iron
• Dissolving of sugar in water

• Baking a cake

Identify the parts of the reaction energy diagram.

a

b

c

d

e

g

h

Endothermic

Activation Energy

Reaction progress

Enthalpy change

Reactants

Products

Exothermic

Energy level

• Exothermic

• Endothermic

Nitrogen reacts with hydrogen to form ammonia.

N₂ + 3H₂ → 2NH₃

The bond energies involved:

H-H : 436 kJ/mol
N≡N : 946 kJ/mol

N-H : 391 kJ/mol

Calculate the enthalpy change, ΔH, for this reaction.

Mathematical Equivalence

ON