Classifying Oxides Quiz

What influences the acidic or basic behavior of an oxide?

Which type of oxides are formed when non-metal elements combine with oxygen?

What type of oxides do metals typically form?

What is the defining characteristic that distinguishes acidic and basic oxides?

Which type of element is most likely to create an acidic oxide?

What type of oxides are formed when a metal element combines with oxygen?

Which group of oxides can behave as both acidic and basic?

When dissolved in water, what type of solution do basic oxides produce?

What happens when amphoteric oxides react with acids?

Which theory can identify acids or bases in situations where substances exhibit both acidic and basic behavior?

Which of the following elements exhibits amphoteric behavior with its oxide?

What is the purpose of leaving the filtrate in a warm place to dry and crystallize?

Which compound is formed when copper(II) oxide reacts with sulfuric acid?

What will happen if copper(II) oxide is added in insufficient amounts to the sulfuric acid?

Which type of base is copper(II) oxide referred to as in the given procedure?

What gas is produced during the reaction of copper(II) oxide and sulfuric acid?

Insoluble Base Preparation

Copper(II) oxide is an insoluble base
To prepare it, add dilute sulfuric acid to a beaker and heat it using a bunsen burner flame
Add copper(II) oxide a little at a time to the warm dilute sulfuric acid and stir until the copper(II) oxide is in excess
Filter the mixture into an evaporating basin to remove the excess copper(II) oxide
Leave the filtrate in a warm place to dry and crystallize
Decant excess solution and blot crystals dry with filter paper

Equation of Reaction

Copper(II) oxide + sulfuric acid → copper(II) sulphate + water
CuO (s) + H2SO4 (aq) → CuSO4 (aq) + H2O (l)

Classifying Oxides

Oxides are compounds made from one or more atoms of oxygen combined with one other element
Examples of oxides include: MgO, ZnO, K2O, CO2, SO2, H2O

Acidic Oxides

Acidic oxides are formed when a non-metal element combines with oxygen
They react with bases to form a salt and water
When dissolved in water, they produce an acidic solution with a low pH
Common examples include CO2, SO2, NO2, and SiO2

Basic Oxides

Basic oxides are formed when a metal element combines with oxygen
They react with acids to form a salt and water
When dissolved in water, they produce a basic solution with a high pH
Common examples include CuO and CaO

Neutral Oxides

Neutral oxides do not react with either acids or bases
Examples include N2O, NO, and CO

Amphoteric Oxides

Amphoteric oxides can behave as both acidic and basic, depending on whether the other reactant is an acid or a base
In both cases, salt and water are formed
Two common amphoteric oxides are zinc oxide (ZnO) and aluminum oxide (Al2O3)
Examples of aluminum oxide behaving as a base and an acid:
- Al2O3 + 6HCl → 2AlCl3 + 3H2O (base)
- Al2O3 + 2NaOH → 2NaAlO2 + H2O (acid)

Test your knowledge on classifying oxides based on their acid-base characteristics. Identify examples of acidic and basic oxides and understand their properties and pH values.