Skip to content
Related Articles

Related Articles

Suspensions

Improve Article
Save Article
  • Last Updated : 16 Nov, 2022
Improve Article
Save Article

Suspension is a heterogeneous mixture of a fluid that contains solute particles that are considerably large for the process of sedimentation. Suspensions are considered to be heterogeneous in nature because they contain at least two different substances. The particles in a suspension are easily visible to the naked eye. The particles are pulled down to the bottom of the container containing the dispersion medium (water). Some of the particles in the suspension sediment to the bottom when the mixture is left. However, suspensions are mixtures where the particles do not settle. 

What is a Suspension?

The size of the particles is generally larger than the particles forming the solution, usually ranging up to one micrometer. The typical diameter in the case of dispersed particles in a suspension is generally 1000 times greater than that of a solution. Since the dissolved particles are larger in size, therefore, they don’t pass through the filter paper. Hence, the physical separation technique of filtration can be used to separate the suspended particles. 

What is a Suspension?

 

Characteristics and Properties of Suspension

  • A heterogeneous mixture is composed of two or more substances.
  • Shows the Tyndall effect due to the large size of the particles.
  • Suspensions are not stable. This is because the particles sediment to the bottom of the solution is left untouched for a while.
  • The particles in the suspension can be separated through physical methods, like the process of filtration.
  • Particles of the solute, in the case of suspension, do not dissolve in the solvent. They remain suspended in bulk throughout the suspension.
  • Suspensions are opaque in nature.
  • Dispersed particles are easily visible to the naked eye. The particle size is greater than 1 nanometer.
  • When the particles settle, it doesn’t scatter light on them.

Examples of Suspension

Some common examples of suspension are as follows: 

  • Oil shaken in the water: Oil shaken in water forms a suspension owing to the difference in nature of the substances forming the suspension. Water molecules are polar in nature, which makes them attracted to each other strongly. This is in reverse to the nature of oil particles, which are nonpolar, or hydrophobic, repelling the water molecules. The water molecules display “stickiness”, which is observed in the movement of two water droplets toward each other. When left undisturbed, the suspension separates out both types of particles.
  • Muddy water
  • Milk of magnesia
  • Sand particles suspended in water
Examples of Suspension

 

  • Dust in the air: This is an example of a solid-gas suspension. The dust particles contain different kinds of particles, like pollen grains or hair. These particles are light in weight and therefore, lifted by wind and ventilation systems. The particles are scattered throughout the air, thereby forming a suspension. These particles eventually settle down to the bottom of the earth.
  • Flour in water
  • Slaked lime for whitewashing
  • Paints in which dyes are suspended in turpentine oil.
  • Soot in the air: Soot is composed of carbon particles emitted through the process of combustion of coal and other carbon-rich energy sources. Also known as black smoke, the soot forms a solid-gas suspension in the air. This is visible in power plants as well as vehicles. The blackening of chimneys is a result of the settling down of soot.

Difference between Suspension, Colloids, and Solution

Difference between Suspension, Colloids, and Solution

 

Property

Suspension

Colloids

Solution

Particle size

Homogeneous

Homogeneous

Homogeneous

Homogeneous/ Heterogeneous Tyndall Effect Brownian

Shows

Shows

Does not Show

Movement

May or may not

Shows

Mostly do not show

Appearance

Opaque

Transparent

Transparent

Settling of particles.

Settles on their own

Settle on centrifugation

Do not settle

Separation by physical methods

Yes

No

No

Visibility

Visible with naked eyes

Not visible to the naked eye.

Visible with the naked eye.

Stability

Unstable

Stable

Stable

Examples

Flour and water mixture

Smoke, Cheese

Sugar and water solution

FAQs on Suspension

Question 1: Define Suspension.

Answer:

Suspensions are heterogeneous systems. The particles of a suspension are very large in size, and are bigger than 100 nm to 200 nm across. These particles are easily visible through the naked eye and have a tendency to settle down under the influence of gravity. Some of the examples of suspensions are sodium chloride in benzene or turmeric in water. 

Question 2: Why is the Tyndall effect visible when sunlight passes through the canopy of a dense forest?

Answer:

Mist is a form of aerosol, which is a suspension of liquid droplets contained in the gas. The tiny droplets of water form the dispersed colloidal particles in the air and therefore, result in the scattering of the light falling on them. Therefore, displaying tyndall effect.

Question 3: Why is mercury shaken in oil considered a suspension?

Answer:

Mercury is a liquid element under standard conditions of temperature and pressure. It is a metallic element that can be mixed with oil in order to create a suspension. The particles will not dissolve, and will eventually separate out. 

Question 4: Define aerosol.

Answer:

A suspension that includes liquid droplets or fine solid particles as the solute dissolved in gas as the solvent is called an aerosol. Examples: fog, mist, or dust. 

Question 5: Why do painters tend to mix the paint before painting the walls?

Answer:

Generally, the size of the particles is greater than 5 x 10-7 m, because they are generally visible with the naked eye. Paint is an example of a suspension. 

Question 6: How can you see and tell whether a mixture is a suspension?

Answer:

Suspensions exhibit some physical properties: 

  • Non-uniform in color
  • Looks cloudy or murky
  • Particles are settled to the bottom

Question 7: Explain the components of the suspension. 

Answer:

Suspensions generally contain two components, the dispersed material, and the dispersion medium. The dispersed material is the solid particle. However, sometimes, it may be in another phase too. The dispersion medium is what the dispersed materials are distributed in, typically equivalent to a solvent.

Related Articles


My Personal Notes arrow_drop_up
Related Articles

Start Your Coding Journey Now!