Question

Which of the following will not form a colloidal system?

• A. Solid-gas
• B. Liquid-gas
• C. Gas-gas
• D. Gas-liquid

Answer 1

The correct option is C Gas-gas

• A colloid is a heterogeneous system in which one substance is dispersed (dispersed phase) as very fine particles in another substance called dispersion medium.
  

• The essential difference between a solution and a colloid is that of particle size. While in a solution, the constituent particles are ions or small molecules. In a colloid, the dispersed phase may consist of particles of a single macromolecule (such as protein or a synthetic polymer) or an aggregate of many atoms, ions or molecules.
  

• Gas-gas colloidal system is not possible as we can't distinguish between the dispersed phase and dispersed medium.