The process of separating the colloidal particles from the solvent and solutes present in the collaidal solution by specially prepared filters, which are permerable to all substances excepts the colloidal particles is known as

Options

A. selective filtration
B. ultrafiltration
C. graded filtration
D. restricted filtration

Answer

B

Explanation

In this method called ultra-filtration, colloidal sols are purified by carrying out filtration through special type of graded filtras called ultra-filters. These filter papers allow only the electrolytes to pass through. Colloidal particles can pass through ordinary filter paper because the pores are too large. Howener, the pores of filter paper can be reduced in size by impregnating ordinary filter paper with collodion solution to stop the flow of colloidal particles.