Difference Between Solutions and Suspensions
By Andrew Parker - August 13, 2022

When describing the relationship between a fluid solvent and a non-fluid solute, one can get a true solution, a suspension, or a colloid. A true solution and a suspension are the closest to physical properties, but there are differences.

Table Summary

SolutionSuspension
A homogenous mixtureA heterogeneous mixture
The solute is invisible to the naked eye, and the microscopeSolute particles are larger than 1,000nm
Does not scatter lightThe mixture refracts the travel of light through it.
It cannot be filtered.The mixtures can be separated by sedimentation and filtration.

Definitions

A true solution is a mixture that is homogenous and has consistent qualities. The particle size of the solute is similar to that of the solvent, which leads to the complete diffusion of the former into the latter, provided certain quantities of solute are not exceeded. Examples of true solutions are salt, sugar, air, and vinegar.

A suspension is a heterogeneous combination in which the solute particles do not dissolve but rather get suspended in the solvent and float about freely in the fluid medium. The internal phase (solid) is disseminated across the exterior phase (fluid) using mechanical agitation and excipients or suspending agents. Examples of suspensions are sea salt, sand in water, and cloud droplets.

Solution VS Suspension

A solution is a homogenous mixture, which is a term that describes the uniform distribution of the solute in the solvent. A suspension is a heterogeneous mixture because it retains the solute and solvents’ phases of matter, e.g., solid and liquid, liquid and gas. Because of the presence of free, large solute particles in the suspension, they can scatter the path of travel of light. This does not take place with solutions. Solutions are also stable. This means there is no solute particle sedimentation when the mixture is brought to rest.