wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Which of the following are methods employed to purify colloids?

A
Dilution
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
Ultrafiltration
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
Peptization
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
Dialysis
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D Dialysis
Electric charge is an important factor for the stability of a colloidal dispersion. Since the dispersed particles carry an equal and opposite charge, they neither aggregate together nor settle down.
In practice, whenever colloidal solutions are prepared, the system also contains some excess electrolytes and other soluble impurities. Hence it is necessary to purify a colloidal solution. The following methods are popular
1. Dialysis: Dialysis may be defined as the process of separating a dissolved solute from a colloid by diffusion or filtration through a fine membrane. The membrane used for the purpose is known as dialyzer. The mixture, taken in a bag made from parchment paper or an animal membrane, is dipped in warm water. Through the parchment paper only true solution solute molecules are able to pass through whereas the colloidal particles remain within the bag. The process of dialysis can be quickened by using hot water, which is called hot dialysis. Alternatively, if we employ an electric field to hasten the dialysis process, then it is termed electrodialysis.
2. Ultrafiltration: Unlike suspensions, the dispersed phase in colloids pass through ordinary filter paper because their pores are larger than the size of sol particles. But if the pores of the ordinary filter paper are clogged partially by soaking the filter paper in a solution of gelatin or collodion and subsequently hardened by soaking in a suitable solvent like formaldehyde, the treated filter paper may retain colloidal particles and allows the true solution particles to escape. Such a filter is known as ultrafilter and the process of separating colloids by using ultrafilters is known as ultrafiltration.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Purification of Colloidal Solution
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon