- More Questions...
- Differentiate Between True Solution, Colloidal Solution and Suspension.
5389 Views
- Give the classification of Colloidal Solutions.
5657 Views
- Differentiate between Lyophilic and Lyophobic Colloids.
5687 Views
- Explain Cleansing action of soap on the basis of micelle formation.
6488 Views
- State Different methods of preparation of Colloidal Solutions.
5812 Views
By Sunil Bhardwaj
7071 Views
A sol contains some electrolyte during its preparation. A small amount of electrolyte is essential for stability of the sol, but excess of it can cause coagulation. Therefore, it is essential to remove excess of electrolyte.
The purification of the sol is done by Dialysis process.
Dialysis: The process of removing the dissolved electrolytes from the sol by means of a membrane is called dialysis. A dialyser consists of a bag made of parchment or cellophane and suspended in running water in a trough. The mixture of the colloid and the crystalloid is taken in the bag and apparatus fitted as shown in Fig. 
After sometime, whole of the crystalloid in solution passes out while the colloid remains in the bag. It is further observed that the above process of separation can be accelerated if an electric field is applied around the parchment bag. The process is then called electrodialysis.
Because of their bigger size, colloidal particles are unable to pass through the parchntent bag while ions of the crystalloid are carried away by the running water in the dialyser. Further on applying the electric field. the movement of the ions is accelerated. 
An important application of dialysis is in the purification of blood in the artificial kidney machine. The dialysis membrane permits small particles to pass through but colloidal haemoglobin does not pass through.
- Write a note on colour of Colloidal Solutions.
5006 Views
- What is Tyndall effect.
6402 Views
- Write a note on Mechanical Properties of Colloidal Solutions.
5394 Views
- Write a note on Electrical Properties of Colloidal Solutions.
9379 Views
- Write a short note on Stability and Protection of Colloids (Coagulation).
5212 Views
- Take a Quiz on "Physical Chemistry"
- More Questions...
Latest News
-
Become an Instructor
4 March, 2018
Apply to join the passionate instructors who share their expertise and knowledge with the world. You'll collaborate with some of the industry's best producers, directors, and editors so that your content is presented in the best possible light..