Problem 14 - A Complete Resource Book in Chemistry for JEE Main

Question

Adsorbed acetic acid on activated charcoal is (a) adsorbate (b) adsorber (c) absorber (d) absorbent

Step-by-Step Solution

Answer

(a) adsorbate

Step 1: Understand the concepts

First, understand what each term in the options means. Adsorbate is the substance being adsorbed on a surface. Adsorber is the material on which the adsorbate accumulates. Absorber refers to a material that incorporates a substance into its entire volume. Absorbent is similar, referring to a substance that can absorb liquids or gases throughout. This question is about adsorption, not absorption.

Step 2: Identify the context

This problem involves acetic acid being adsorbed on activated charcoal. In adsorption, the substance (acetic acid) is adsorbed onto the surface of another material (activated charcoal). Since acetic acid is the substance being adsorbed, we identify acetic acid according to adsorption terminology.

Step 3: Match the term

From the context, match acetic acid to the appropriate term based on its role. As acetic acid is accumulating on the surface, it is being adsorbed. Therefore, acetic acid is the adsorbate in this scenario.

Key Concepts

Adsorbate

The term "adsorbate" refers to any substance that accumulates on the surface of another material during a process called adsorption. Unlike absorption, where a substance is fully integrated into the volume of another material, adsorption involves just the surface layer.

• Adsorbates can be gases, liquids, or dissolved solids.
• They can adhere to the surfaces of solids, such as metals or porous materials like activated charcoal.

In our exercise, the adsorbate is acetic acid because it is the substance being deposited on the surface of activated charcoal. This is a classic example of adsorption, where the unique properties of the solid surface attract and hold the acetic acid molecules.
Understanding the role of adsorbates is key in surface chemistry, influencing how cleaning agents work, how pollutants are captured, and even how flavors are absorbed by certain materials.

Activated Charcoal

Activated charcoal is a form of carbon processed to have small, low-volume pores, increasing the surface area available for adsorption. It is a powerful adsorbent material, capable of trapping various molecules and particles from gases and liquids.

• The high porosity of activated charcoal makes it an ideal adsorbent for purifying substances by removing impurities, colors, and odors.
• It is frequently used in water filters, air purifiers, and even in medical treatments to absorb toxins.

When discussing our scenario, activated charcoal acts as the substrate, providing the surface onto which the acetic acid—the adsorbate—adheres. This shows the effective nature of activated charcoal in surface chemistry applications, where it acts as the base that enables adsorption.

Surface Chemistry

Surface chemistry studies the physical and chemical processes occurring at surfaces and interfaces. It plays a crucial role in understanding adsorption phenomena.

• In adsorption, the surface chemistry of the adsorbent—like activated charcoal—determines how well different substances are adsorbed.
• The interactions can be physical, with weak van der Waals forces, or chemical, involving stronger homogeneous bonds.

In our example, the interaction between the surface of activated charcoal and acetic acid molecules is governed by surface chemistry principles. By studying these interactions, scientists can develop better materials for capturing pollutants, delivering drugs at specific targets, or even creating sensors that detect chemical changes in the environment. Understanding surface chemistry allows us to design materials with desired properties, impacting various fields from environmental science to medicine.