Column - I and Column - II contains four emtries each. Entries of Column -I are to be matched with some entries of Column - II . One or more than one entries of Column -I may have the matching with the same entries of Column - II.
`{:("column-I","column-II"),("(A) peptization ","(P) preparation of sols "),("(B) Ultra centrifugation ",(Q) " Purification of sols "),("(C) Electrodialysis","(R) perparation of metal sols "),("(D) Breding's arc method ","(S) movement of ions acress the membrane in prsence of electric field "):}`

Answer

To solve the matching question between Column - I and Column - II, we need to analyze each entry in Column - I and find the corresponding matches in Column - II based on the definitions and processes involved in surface chemistry.

### Step-by-Step Solution:

1. **Peptization (A)**:
- **Definition**: Peptization is the process of converting a precipitate into a colloidal solution by the addition of a suitable dispersing agent.
- **Match**: This process is directly related to the preparation of sols.
- **Conclusion**: Matches with **(P) Preparation of sols**.

2. **Ultra Centrifugation (B)**:
- **Definition**: Ultra centrifugation is a technique used to separate particles from a solution based on their size and density by spinning them at high speeds.
- **Match**: This method is primarily used for the purification of sols, as it helps in separating impurities from the colloidal solution.
- **Conclusion**: Matches with **(Q) Purification of sols**.

3. **Electrodialysis (C)**:
- **Definition**: Electrodialysis is a process that uses an electric field to drive the movement of ions through selective ion-exchange membranes.
- **Match**: This process involves the movement of ions across the membrane in the presence of an electric field, which is a key characteristic of electrodialysis. Additionally, it can also be used for the purification of sols.
- **Conclusion**: Matches with **(S) Movement of ions across the membrane in presence of electric field** and **(Q) Purification of sols**.

4. **Breding's Arc Method (D)**:
- **Definition**: Breding's arc method is a technique used for the preparation of metal sols, such as gold or silver sols, by generating an arc between two electrodes in a liquid medium.
- **Match**: This method is used for the preparation of sols, specifically metal sols.
- **Conclusion**: Matches with **(P) Preparation of sols** and **(R) Preparation of metal sols**.

### Final Matches:
- (A) Peptization → (P) Preparation of sols
- (B) Ultra Centrifugation → (Q) Purification of sols
- (C) Electrodialysis → (S) Movement of ions across the membrane in presence of electric field, (Q) Purification of sols
- (D) Breding's Arc Method → (P) Preparation of sols, (R) Preparation of metal sols

### Summary of Matches:
- **(A) → (P)**
- **(B) → (Q)**
- **(C) → (S), (Q)**
- **(D) → (P), (R)**