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AAT Bioquest

What are the differences between solution and colloid?

Posted March 17, 2023


Answer

Solution and colloid are two types of mixtures. In both mixtures, the solute molecules can be physically recovered as they are not chemically bonded to the solvent molecules. There are several differences between solution and colloid.

Basis of differentiation 

Solution 

Colloid 

Definition 

Is a homogeneous mixture made up of one or more solutes in a solvent

Is a heterogeneous mixture made up of particles that are dispersed or suspended in the dispersion medium

Phase

Consists of a single phase

Consists of two distinct phases - a dispersed phase that contains suspended particles, and a continuous phase, which is the suspension or dispersion medium

Components 

Has two components - Solute and solvent

Has two components – a dispersed phase and a dispersion medium

Nature 

Homogeneous 

Heterogeneous 

Interaction between the particles

Solute and solvent particles interact through attractive intermolecular forces such as Vander Waals forces, hydrogen bonding, and ion-induced dipole forces

Colloid particles interact through electrostatic interaction, steric forces, excluded volume repulsion, and Vander Waals forces

Particle size

Particle sizes are very small, less 1 nanometer

Particle sizes are larger, usually 1- 200 nanometer

Permeability 

Is permeable through most membranes

Is permeable only through ultrafiltration papers

Diffusion 

Particles diffuse rapidly

Particles diffuse slowly

Tyndall effect 

Does not exhibit Tyndall effect -  Light passes through solutions

Exhibits Tyndall effect - Light is scattered by larger particles

Appearance of the system

Clear, transparent

Cloudy, translucent

Visibility 

Particles are invisible to the naked eye and are not visible even under a light microscope

Particles are invisible to the naked eye but visible under a light microscope

Sedimentation 

Particles do not settle down after centrifugation

Particles usually settle down after centrifugation

Filtration

Particles cannot be separated through ordinary or parchment filters

Particles can be separated through a parchment filter

Examples

- Brine is a homogeneous mixture containing salt and water

- Honey is a homogenous mixture of sugars (glucose and fructose) and other carbohydrates

- Soda is a homogenous solution comprising carbon dioxide and water 

 

- Milk is a colloidal mixture made up of protein globules and dispersed liquid fat in water

- Ice cream is a colloidal mixture made up of ice crystals, fat globules, and air bubbles

- Blood is a colloid containing blood plasma and blood cells such as red blood cells, white blood cells and platelets

Additional resources

A colloidoscope of colloid-based porous materials and their uses

Solubility Reference Table

Serial Dilution Calculator and Planner