Question

Assertion: Aqueous gold colloidal solution is red in colour.

Answer 1

colour of colloidal solution depends on the wavelength of light scattered by the dispersed particles. The wavelength of light further depends on the size and nature of the particles. Finest gold sol is red in colour. As size of the particles increases, it becomes purple, then blue and finally golden yellow.

Answer 2

Answer:

(1) The colour of a colloidal solution arises due to scattering of light.

(2) The colour depends upon the wavelengthnof light scattered by dispersed or (colloidal)nparticles

(3) The colour depends on size of colloidal particles. For example gold sol changes colour from red to purple as size of it increases.

(4) The colour of colloidal sol depends on the manner in which the observer receives the scattered light. For example, a mixture of a few drops of milk and large amount of water appears blue when scattered light is observed while it appears red when transmitted light is observed.