1.what is a tyndall effect ?
rn2.what is turbidity of a substance?
A-1) Tyndall effect is the phenomenon of scattering of light by the particles of colloid or suspension because of which the path of light is illuminated. The tiny particles scatter the beam of light and make its path visible. For example: Tyndall effect can be observed when sunlight passes through the canopy of a dense forest. In the forest, mist contains tiny droplets of water, which act as particles of colloid dispersed in air.
The particles of dust and smoke in air scatter light, thereby causing Tyndall effect.
A-2) Turbidity is basically defined as milkiness or cloudiness that appears in a solution due to the formation of a precipitate, because of which a solution does not appear clear. For example, when carbon dioxide gas is passed through lime water, it turns turbid due to the formation of calcium carbonate which is insoluble in water. Following is the chemical equation for the reaction
Ca(OH)2 + CO2 → CaCO3 + H2O