Question

Hydrophilic colloids are stable due to:
$A.$ Negative charged particles
$B.$ Large size of particles
$C.$ Small size of particles
$D.$ Layer of dispersion medium on their particles.

Answer 1

**:Colloidal solution is defined as the mixture which one of the substances dispersed into very microscopic particles which are dispersed throughout a second substance. The minute particles are known as colloidal particles. Based on interaction, colloidal solutions can be classified as lyophilic and lyophobic. If the dispersed phase is water these terms are known as hydrophilic and hydrophobic.

Complete answer:
Hydrophilic colloids are water loving colloids. These colloid particles are attracted toward water. They are also called reversible sols. The stability of a colloidal system is the capability of the system to remain as it is. Stability is hindered by aggregation and sedimentation phenomena, which are driven by the colloid tendency to reduce surface energy
Hydrophilic colloids are stable due to a layer of dispersion medium on their particles.

So, the correct option is $D.$

Note:
A colloidal solution is a heterogeneous mixture of two or more substances. They are translucent, size of the particles range from $1nm - 100nm$ .Particles are invisible to naked eye but are visible under powerful microscopes. These particles can be separated from filtering through parchment paper. Particles can settle at the bottom of the container via centrifugation and the Brownian effect can be observed.
The colloidal solution is used as therapeutic agents in different areas. For example silver colloidal is used as germicidal whereas copper colloidal is used as anticancer.
Note: The main reason for the stable of colloidmass of a dispersed phase is so low that its buoyancy or kinetic energy is too weak to overcome the electrostatic repulsion between charged layer of the dispersing phase.