Overview
Unit covers formation, concentration, and properties of solutions, focusing on liquid
solutions.
Learning outcomes include describing solution types, concentration units, Henry’s and
Raoult’s laws, ideal vs non-ideal solutions, deviations from Raoult’s law, colligative
properties, and abnormal colligative effects.
Types Of Solutions
Solution: homogeneous mixture with uniform composition and properties.
Solvent: component in largest quantity; determines physical state.
Solute(s): other component(s); binary solutions contain two components.
Classification by states of solute and solvent: gaseous, liquid, solid solutions with typical
examples.
Phase Of Solution Solute Solvent Example
Gaseous Gas Gas O2 + N2 mixture
Liquid Gas Liquid O2 dissolved in water
Liquid Liquid Liquid Ethanol in water
Liquid Solid Liquid Glucose in water
Solid Gas Solid H2 in Pd
Solid Liquid Solid Amalgam (Hg + Na)
Solid Solid Solid Cu in Au (alloy)
Expressing Concentration
Mass percent (w/w): mass component / total mass × 100.
Example: 10% (w/w) glucose → 10 g glucose + 90 g water = 100 g solution.
Volume percent (v/v): volume component / total volume × 100.
Common for liquid–liquid solutions.
, Mass by volume (w/V): mass solute per 100 mL solution; used in medicine.
Parts per million (ppm): parts of component × 10^6 / total parts; useful for trace
concentrations.
Mole fraction (x): moles component / total moles; useful in vapour-pressure and gas-
mixture calculations.
Sum of mole fractions = 1.
Molarity (M): moles solute / litres of solution; temperature-dependent.
Molality (m): moles solute / kg solvent; temperature-independent.
Concentration Unit Definition Temperature Dependence
Mass % (w/w) Mass component / total mass × 100 Independent
Volume % (v/v) Volume component / total volume × 100 Dependent (volumes change)
Mass/Volume (w/V) Mass solute per 100 mL solution Dependent
ppm Parts × 10^6 / total parts Independent
Mole Fraction (x) Moles component / total moles Independent
Molarity (M) Moles solute / L solution Dependent
Molality (m) Moles solute / kg solvent Independent
Solubility: Basic Concepts
Solubility: maximum amount dissolvable in specified solvent at specified temperature and
pressure.
Dissolution and crystallisation occur until dynamic equilibrium: Solute + Solvent ⇌ Solution.
Saturated solution: in dynamic equilibrium with undissolved solute; unsaturated: can
dissolve more solute.
Factors Affecting Solubility
Nature of solute and solvent: "like dissolves like" (polar in polar; nonpolar in nonpolar).
Temperature:
Unit covers formation, concentration, and properties of solutions, focusing on liquid
solutions.
Learning outcomes include describing solution types, concentration units, Henry’s and
Raoult’s laws, ideal vs non-ideal solutions, deviations from Raoult’s law, colligative
properties, and abnormal colligative effects.
Types Of Solutions
Solution: homogeneous mixture with uniform composition and properties.
Solvent: component in largest quantity; determines physical state.
Solute(s): other component(s); binary solutions contain two components.
Classification by states of solute and solvent: gaseous, liquid, solid solutions with typical
examples.
Phase Of Solution Solute Solvent Example
Gaseous Gas Gas O2 + N2 mixture
Liquid Gas Liquid O2 dissolved in water
Liquid Liquid Liquid Ethanol in water
Liquid Solid Liquid Glucose in water
Solid Gas Solid H2 in Pd
Solid Liquid Solid Amalgam (Hg + Na)
Solid Solid Solid Cu in Au (alloy)
Expressing Concentration
Mass percent (w/w): mass component / total mass × 100.
Example: 10% (w/w) glucose → 10 g glucose + 90 g water = 100 g solution.
Volume percent (v/v): volume component / total volume × 100.
Common for liquid–liquid solutions.
, Mass by volume (w/V): mass solute per 100 mL solution; used in medicine.
Parts per million (ppm): parts of component × 10^6 / total parts; useful for trace
concentrations.
Mole fraction (x): moles component / total moles; useful in vapour-pressure and gas-
mixture calculations.
Sum of mole fractions = 1.
Molarity (M): moles solute / litres of solution; temperature-dependent.
Molality (m): moles solute / kg solvent; temperature-independent.
Concentration Unit Definition Temperature Dependence
Mass % (w/w) Mass component / total mass × 100 Independent
Volume % (v/v) Volume component / total volume × 100 Dependent (volumes change)
Mass/Volume (w/V) Mass solute per 100 mL solution Dependent
ppm Parts × 10^6 / total parts Independent
Mole Fraction (x) Moles component / total moles Independent
Molarity (M) Moles solute / L solution Dependent
Molality (m) Moles solute / kg solvent Independent
Solubility: Basic Concepts
Solubility: maximum amount dissolvable in specified solvent at specified temperature and
pressure.
Dissolution and crystallisation occur until dynamic equilibrium: Solute + Solvent ⇌ Solution.
Saturated solution: in dynamic equilibrium with undissolved solute; unsaturated: can
dissolve more solute.
Factors Affecting Solubility
Nature of solute and solvent: "like dissolves like" (polar in polar; nonpolar in nonpolar).
Temperature:
