Question

does alum solution show tyndall effect

Answer 1

Yes alum shows Tyndall effect. Alum is a colloidal solution in water and is translucent.

It is used to purify water. In fact it is used to attract colloids from the liquid and thus separating them. (It is added to the water so that the negatively charged colloidal particles clump together into "flocs", which then float to the top of the liquid, settle to the bottom of the liquid, or can be more easily filtered from the liquid, prior to further filtration and disinfection of the water.)