i) The Tyndall effect is the scattering of light as a light beam passes through acolloid. The individual suspension particles scatter and reflect light, making the beam visible.

The amount of scattering depends on thefrequencyof the light anddensityof the particles. As with Rayleigh scattering, blue light is scattered more strongly than red light by the Tyndall effect. Another way to look at it is that longer wavelength light is transmitted, while shorter wavelength light is reflected by scattering.

ii)Solubilityis the property of asolid,liquidorgaseouschemical substancecalledsoluteto dissolve in a solid, liquid or gaseoussolvent. The solubility of a substance fundamentally depends on the physical and chemical properties of the solute and solvent as well as on temperature, pressure and presence of other chemicals (including changes to thepH) of the solution. The extent of the solubility of a substance in a specific solvent is measured as thesaturationconcentration, where adding more solute does not increase the concentration of the solution and begins to precipitate the excess amount of solute.