Colligative Properties and Colloids in Chemistry

Colligative Properties

Properties depending on total solute particle number.

Solute Particles

Particles dissolved in a solvent affecting properties.

Freezing Point Depression

Decrease in freezing point due to solute presence.

Boiling Point Elevation

Increase in boiling point due to solute presence.

Vapor Pressure Depression

Reduction in vapor pressure from solute addition.

Osmotic Pressure

Pressure needed to stop solvent flow through membrane.

Molarity

Moles of solute per liter of solution.

Molality

Moles of solute per kilogram of solvent.

Osmolarity

Molarity multiplied by number of ions produced.

Physiological Saline

0.89% NaCl solution matching blood cell content.

Hypertonic Solutions

Osmolarity greater than 0.30.

Isotonic Solutions

Osmolarity equal to 0.30.

Hypotonic Solutions

Osmolarity less than 0.30.

Dissociation of Compounds

Separation of solute into ions in solution.

Conductivity

Measure of ion presence in a solution.

Semipermeable Membrane

Allows solvent passage, blocks larger solute particles.

Reverse Osmosis

Pressure-driven solvent flow against concentration gradient.

k_f

Freezing point depression constant for a solvent.

k_b

Boiling point elevation constant for a solvent.

Ionization Factor (i)

Number of ions produced from one solute unit.

NH4Br

Dissociates into 2 ions, osmolarity 0.30.

AlCl3

Dissociates into 4 ions, osmolarity 0.30.

C6H12O6

Does not dissociate, osmolarity 0.30.

Mg3(PO4)2

Dissociates into 5 ions, osmolarity 0.30.

Osmotic Pressure Effects

Impact of osmotic pressure on cell behavior.

Ions in Solution

The charged particles that result from the dissociation of a solute in a solvent.

KCl

A compound that produces 2 ions (K+ and Cl-) in solution.

MgI2

A compound that produces 3 ions (Mg2+ and 2I-) in solution.

Na3PO4

A compound that produces 4 ions (3Na+ and PO43-) in solution.

Al2(SO4)3

A compound that produces 5 ions (2Al3+ and 3SO42-) in solution.

Conductivity Data

Measurements of conductivity for various compounds at 0.01M concentration, expressed in units of 10^-4 m2 S/mol.

NaCl Conductivity

119 (10^-4 m2 S/mol) for 0.01M NaCl.

KCl Conductivity

141 (10^-4 m2 S/mol) for 0.01M KCl.

MgCl2 Conductivity

229 (10^-4 m2 S/mol) for 0.01M MgCl2.

CaCl2 Conductivity

241 (10^-4 m2 S/mol) for 0.01M CaCl2.

HCl Conductivity

412 (10^-4 m2 S/mol) for 0.01M HCl.

KNO3 Conductivity

133 (10^-4 m2 S/mol) for 0.01M KNO3.

NaOH Conductivity

238 (10^-4 m2 S/mol) for 0.01M NaOH.

KOH Conductivity

228 (10^-4 m2 S/mol) for 0.01M KOH.

Colligative Property

A property that depends on the number of solute particles in a solution, not their identity.

Bond Polarity

The difference in electronegativity between bonded elements, affecting solubility.

Likes Dissolve Likes

The principle that polar solvents dissolve polar solutes, and non-polar solvents dissolve non-polar solutes.

Dielectric Constant

A measure of a solvent's ability to reduce the electrostatic forces between charges, indicating polarity.

Water Dielectric Constant

80, indicating high polarity.

Methanol Dielectric Constant

33, indicating moderate polarity.

Ethanol Dielectric Constant

24.4, indicating lower polarity.

Colloid

A mixture of small particles dispersed in another medium, ranging from 1 nm to 1 μm.

Tyndall Effect

The scattering of light by particles in a colloid, used to identify colloids.

Soap

A large organic molecule with a polar end and a non-polar end, acting as a cleaning agent.

Saponification

The base-catalyzed hydrolysis of ester groups in triglycerides to form soap.

Micelle

The structure formed when a fatty acid salt surrounds a grease particle, making it water soluble.