Colloid vs. Suspension: What's the Difference?
Edited by Aimie Carlson || By Harlon Moss || Published on November 28, 2023
A colloid is a mixture with particle sizes between 1 nm and 1000 nm that don't settle out. A suspension contains larger particles that will settle over time unless agitated.
Key Differences
A colloid comprises tiny particles dispersed throughout another substance, where these particles are larger than molecules but too tiny to be seen easily, staying dispersed without settling out. On the contrary, a suspension contains particles that are large enough to be seen and, given time, these particles will settle to the bottom unless the suspension is continually agitated.
The properties of a colloid arise because its particles are spread evenly throughout the solution, and they won't settle or separate on standing. Suspensions, however, differ in this aspect, as their particles will settle if the mixture is allowed to stand without disturbance.
The particles in a colloid are often electrically charged, which prevents them from aggregating and settling out of the mixture. In contrast, particles in a suspension are usually larger and lack this charge, making them susceptible to the pull of gravity and eventually settling.
The Tyndall effect, where light is scattered by particles in a mixture, is commonly seen in colloids due to their intermediate particle size. Suspensions, due to their larger particle size, may also show this effect, but their particles will eventually settle, changing the mixture's appearance.
When it comes to filtration, separating particles from a colloid can be challenging, often requiring special techniques or ultra-filtration. In a suspension, simple filtration can typically separate the particles from the dispersing medium, given their larger size.
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Comparison Chart
Particle Size
Between 1 nm and 1000 nm.
Larger than those in colloids.
Settling of Particles
Particles don't settle due to their small size.
Particles will settle over time unless stirred.
Visibility
Particles are too small to be seen with the naked eye.
Particles are visible and often make the mixture cloudy.
Tyndall Effect
Shows the Tyndall effect due to intermediate particle size.
May show the effect, but particles eventually settle.
Filtration
Hard to separate particles through regular filtration.
Particles can be separated through simple filtration.
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Colloid and Suspension Definitions
Colloid
A mixture in which microscopically dispersed insoluble particles are suspended throughout another substance.
Milk is a colloid where fat droplets are dispersed in water.
Suspension
A mixture in which particles are dispersed in a fluid and will settle over time.
Muddy water is a suspension of soil in water.
Colloid
A system in which particles are dispersed in a continuous phase of a different composition.
Whipped cream is a colloid of air in cream.
Suspension
A system in which solid particles are present in a liquid or gas medium.
Orange juice with pulp is a suspension with bits of fruit in the liquid.
Colloid
A material that comprises two phases, with one dispersed continuously through the other.
Gelatin desserts are colloids where liquid water is dispersed in solid gelatin.
Suspension
A heterogeneous mixture containing larger particles that aren't dissolved.
Chalk in water forms a suspension that will separate over time.
Colloid
A substance with components of intermediate size between a solution and a suspension.
Mayonnaise is a colloid consisting of oil and vinegar.
Suspension
A state in which particles are temporarily dispersed in a medium.
Medicines often have active ingredients in suspension for even distribution.
Colloid
A stable dispersion of particles, often having properties different from those of the individual components.
Butter is a colloid with a different texture and taste than its ingredients.
Suspension
A mixture where internal phases have differences in density, causing settling if undisturbed.
Sand in water quickly settles, forming a clear suspension.
Colloid
A system in which finely divided particles, which are approximately 1 to 1,000 millimicrons in size, are dispersed within a continuous medium in a manner that prevents them from being filtered easily or settled rapidly.
Suspension
An interruption or temporary cessation, as of an activity or of the application of a rule or law.
Colloid
The particulate matter so dispersed.
Suspension
A temporary prohibition or exclusion, as from attending school or enjoying a privilege, especially as a punishment.
FAQs
Can you typically filter out particles from a colloid using regular filtration?
No, colloidal particles are too small for regular filtration.
Which mixture shows the Tyndall effect due to intermediate-sized particles?
Colloids exhibit the Tyndall effect because of their particle size.
Do particles in a colloid settle over time?
No, particles in a colloid remain dispersed and don't settle.
In which mixture will gravity pull particles to the bottom?
In a suspension, gravity can pull the larger particles to the bottom.
What kind of charge do particles in colloids often have?
Colloidal particles often have an electrical charge.
Is whipped cream a colloid or suspension?
Whipped cream is a colloid.
Do colloids enhance the stability of products in the food industry?
Yes, colloids can improve stability, texture, and appearance in foods.
If a mixture's particles settle when left undisturbed, is it a colloid or suspension?
It's a suspension, as particles in suspensions can settle over time.
How do the properties of a suspension change if it's left undisturbed?
Particles in a suspension will settle at the bottom, making it less uniform.
Which one can be separated using simple filtration: colloid or suspension?
Suspensions can be separated using simple filtration.
Can you give an example of a gaseous colloid?
Fog is a gaseous colloid with tiny water droplets dispersed in air.
Can you easily see particles in a suspension?
Yes, particles in a suspension are usually large enough to be visible.
Which is more stable: a colloid or a suspension?
A colloid is more stable, as its particles don't settle out.
Are the particles in butter considered colloidal?
Yes, butter is a colloid with water in a fat matrix.
How do particles in a suspension interact with a dispersing medium?
They're dispersed but will settle out over time if undisturbed.
If you shake a suspension, will the particles redisperse?
Yes, shaking can temporarily redisperse particles in a suspension.
Which is typically more opaque: a colloid or a suspension?
A suspension is typically more opaque due to its larger particles.
What's a key visual difference between a colloid and suspension?
Suspensions are often cloudy with visible particles, while colloids are usually consistent.
Is milk an example of a colloid or suspension?
Milk is an example of a colloid.
What happens when light passes through a colloid?
A colloid can scatter light, demonstrating the Tyndall effect.
About Author
Written by
Harlon MossHarlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Aimie CarlsonAimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.
