Question

Assertion :The dialysis a technique for purification of sol is used to remove the soluble and insoluble impurities present in sol. Reason: The dialysis is based on different rate of diffusion of true solution and collodial solution particles.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is D Assertion is incorrect but Reason is correct

We have already seen that an animal membrane allows the passage of crystalloids but retains the larger colloidal particles. This property of animal membranes is utilized for the purification of sols. The process involved is called dialysis.

It may be defined as follows.

The process of separating the impurity particles of true solution dimensions (crystalloids) from an impure sol by means of diffusion through a suitable membrane such as parchment paper or cellophane membrane is called dialysis.

The apparatus used in this method is called dialyzer. It consists of a bag made of parchment or cellophane. The bag is filled with the impure sol to be purified and is suspended in a tank through which pure water is circulated. The impurities of electrolytes present in the sol diffuse out of the bag leaving behind pure sol in the bag.