Adsorption
Chapter Name : Surface Chemistry |
Sub Topic Code : 102_12_05_02_03 |
Topic Name : Adsorption |
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Sub Topic Name : Mechanism Of Adsorption |
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Introduction
• Adsorption is a surface phenomenon which occurs due to presence of residual attractive forces on the surface of adsorbent. • Adsorption is an exothermic process and thus heat is released when it occurs.
Pre-Requisites:
• Introduction of adsorption • Gibbs free energy equation
Activity:
If a sachet of silica gel is kept near a pot of boiling water, all the water vapor generated due to boiling gets adsorbed by the silica gel.
Real Life Question:
When silica gel is kept in a humid environment, why does the surrounding air turn dry?
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. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Silica gel | Keep a sachet of silica gel near a pot of boiling water. |
| A pot of boiling water | For generation of water vapour. |
Real life uses :
Treatment of waste water.
Places to visit :
Water treatment plant.
Practical examples around us
| Examples | Explainations |
|---|---|
| Water treatment plant | Cleaning of wastewater is done using activated carbon (char-like material). Pollutants in the water get adsorbed on the surface of carbon leading to cleansing of water. |
What you learn in Theory:
Factors that govern the process of adsorption.