Surface Chemistry

Question

The conditions given below are in the context of observing Tyndall effect in colloidal solutions :

(A) The diameter of the colloidal particles is comparable to the wavelength of light used.

(B) The diameter of the colloidal particles is much smaller than the wavelength of light used.

(C) The diameter of the colloidal particles is much larger than the wavelength of light used.

(D) The refractive indices of the dispersed phase and the dispersion medium are comparable.

(E) The dispersed phase has a very different refractive index from the dispersion medium.

Choose the most appropriate conditions from the options given below :

Accepted Answer

Option A. The phenomenon of scattering of light by colloidal particles as a result of which the path of the
beam becomes visible is called a tyndall effect. Smaller the diameter and similar the magnitude
of refractive indices, lesser is the scattering and hence the tyndall effect and viced-versa. The
diameter of the dispersed phase particle should not be smaller than the wavelength of light
used because they won't be able to scatter the light so, therefore, the diameter of the dispersed
particles should be equal or not much smaller than the wavelength of the light used.

More on Surface Chemistry

Surface Chemistry

More on Surface Chemistry