SOLUBILITY PART 1

What is a solution?

A solution is a homogeneous mixture, meaning it has the same composition and properties throughout.

Why are solutions considered homogeneous mixtures?

Because they are uniform throughout and have the same composition and properties everywhere.

What are the two components of a solution?

A solute and a solvent.

What is a solute?

The substance being dissolved, usually the smaller amount.

What is a solvent?

The substance that does the dissolving, usually the larger amount.

What are the two main types of solutions?

Ionic solutions and molecular solutions.

What is an ionic solution?

A solution that contains ions and conducts electricity (electrolyte).

Why do ionic solutions conduct electricity?

Because they contain free-moving ions.

What types of elements make up ionic compounds?

A metal and a non-metal.

What happens when NaCl dissolves in water?

NaCl(s) dissociates into Na⁺(aq) and Cl⁻(aq).

What is a molecular solution?

A solution that contains neutral molecules and does not conduct electricity.

Why do molecular solutions not conduct electricity?

Because they do not form ions in solution (non-electrolytes).

What types of elements make up molecular compounds?

Only non-metals (covalent compounds).

What happens when C₁₂H₂₂O₁₁ dissolves in water?

C₁₂H₂₂O₁₁(s) dissolves as intact molecules to form C₁₂H₂₂O₁₁(aq).

What is solubility?

The maximum amount of a substance that can dissolve in a given amount of solvent at a given temperature.

What does it mean when a solution is saturated?

It contains the maximum amount of dissolved solute possible at that temperature.

What happens if more solute is added to a saturated solution?

The extra solute will not dissolve and will remain as a solid.

When does saturation exist in a solution?

When undissolved solid is present and equilibrium exists between dissolved ions and solid.

What are the two conditions required for a saturated solution?

Undissolved solid must be present and the rate of dissolving equals the rate of precipitation.

What does equilibrium mean in a saturated solution?

The rate of dissolving equals the rate of crystallization.

What happens to a salt when it dissolves in water?

It separates into its positive and negative ions.

How is a saturated solution shown using an equation?

By writing the solid in equilibrium with its aqueous ions.

What does the equilibrium equation Ag₂SO₄(s) ⇔ 2Ag⁺(aq) + SO₄²⁻(aq) represent?

A saturated solution where dissolving and crystallization occur at equal rates.

What is the dissolving reaction for Ag₂SO₄?

Ag₂SO₄(s) → 2Ag⁺(aq) + SO₄²⁻(aq).

What is the crystallization reaction for Ag₂SO₄?

2Ag⁺(aq) + SO₄²⁻(aq) → Ag₂SO₄(s).

Which reaction dominates at the beginning of dissolving?

The dissolving reaction.

Why does the crystallization reaction speed up over time?

Because ion concentration in solution increases.

When is equilibrium finally reached?

When the dissolving rate equals the crystallization rate.

How are salts categorized based on solubility?

Either soluble or low solubility.

What happens to soluble salts in water?

They remain dissolved as ions and do not precipitate.

What happens to salts with low solubility in water?

They dissolve only slightly and tend to form solid precipitates.

What tool is used to predict salt solubility?

The solubility table in the Chemistry 12 data booklet.

At what temperature does the solubility table apply?

25°C.

What does the solubility table tell us?

Which salts are soluble and which have low solubility.

When is a substance considered to have low solubility?

When a saturated solution has a concentration less than 0.1 M.

How do you predict if a precipitate will form when mixing solutions?

Check the solubility of the resulting salt using the solubility table.

When will a precipitate form?

When the resulting compound has low solubility.

What causes precipitation during mixing of salt solutions?

Two ions forming a compound with low solubility.