Adsorption
Chapter Name : Surface Chemistry |
Sub Topic Code : 102_12_05_02_06 |
Topic Name : Adsorption |
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Sub Topic Name : Adsorption From Solution Phase |
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Introduction
• Along with gases, solids can also adsorb solute from the solutions. • The extent of adsorption of solute depends upon numerous factors such as temperature, surface area of adsorbent, the nature of both adsorbent and adsorbate and also on the concentration of solute. • The behavior of adsorption of solute in a solution can be understood using the Freundlich Adsorption Isotherm. .
Pre-Requisites:
• Introduction of adsorption. • Adsorption mechanism. • Adsorption isotherms.
Activity:
When charcoal is added to acetic acid, its concentration decreases. This concentration is then measured. The difference b/w the initial and final concentration gives us the extent of adsorption in solution.
Real Life Question:
How does adsorption of solute from a solution take place?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Adsorption | It is the phenomenon of accumulation of molecules of a liquid/gas on the surface of a solid. |
| Adsorbate | It is the substance which concentrates or accumulates at the surface of another substance. |
| Adsorbent | It is the substance on which adsorption occurs i.e. on which another substance gets accumulated. |
| Adsorption isotherm | It is the graph between the amounts of adsorbate (x) adsorbed on the surface of adsorbent (m) and concentration at constant temperature. |
| Freundlich Adsorption Isotherm | It is an empirical relationship between the amount of solute adsorbed by unit mass of solid adsorbent and concentration at a particular temperature. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Acetic acid solution of different concentrations | Take equal quantities of different concentration of acetic acid solution in different flasks. |
| Activated charcoal | To each flask add equal amount of charcoal. |
Real life uses :
Refining of edible oil, sugar.
Places to visit :
Laboratory.
Practical examples around us
| Examples | Explainations |
|---|---|
| Refining of edible oils | Purification of organic compounds is done by adsorption of impurities on solid surface. |
What you learn in Theory:
Adsorption of solute particles from the solution on the solid surface.
What you learn in Practice:
How adsorption from solution phase is used for cleansing of compounds.