Question

The formation of colloid from suspension is: (a) peptisation (b) condensation (c) sedimentation (d) fragmentation

Short answer

The formation of colloid from suspension is known as peptisation.

Step-by-step solution

Understanding Terms

Firstly, understand the terms involved in this question. A colloid is a mixture where one substance of microscopically dispersed insoluble or soluble particles is suspended throughout another substance. 'Peptisation' refers to the process of converting a precipitate into a colloid under the influence of an electrolyte. 'Condensation' is a process where gas turns to a liquid, which does not relate to the formation of colloids directly. 'Sedimentation' is the process of settling or being deposited as a sediment, which is the opposite of forming a stable suspension. 'Fragmentation' is the process of breaking into fragments and typically does not pertain to the formation of colloids.

Identify the Process

Next, identify which process is responsible for forming a colloid from a suspension. The formation of a colloid can be achieved when particles are evenly dispersed throughout a solution, which can occur through the process of peptisation. Hence, the term that best describes the conversion of a precipitate into a colloid is peptisation.

Choose the Correct Answer

Based on the understanding of terms and the identified process responsible for the formation of colloids from a suspension, the correct answer can be decided. The term 'peptisation' exactly describes the process of forming a colloid from a suspension.

Key concepts

Colloid Formation

Colloid formation is a fundamental concept in physical chemistry, vital for students to understand. When we talk about colloid formation, we're looking at how substances mix together to create a system where minute particles are dispersed throughout another substance without settling out. The process is not as simple as just mixing two components; a specific procedure must take place for a true colloidal solution to form.

One such procedure is peptisation. This unique process involves taking a precipitate, which is typically a solid that has settled out of a solution, and adding an electrolyte to it. An electrolyte is often an acid, base, or salt capable of dissociating into ions. These ions adsorb onto the surface of the precipitate, which imparts an electric charge to the particles. This charge prevents the particles from clumping together, allowing them to remain suspended within the solvent, effectively forming a colloid.

It's worth noting that peptisation can happen naturally or induced through chemical manipulation. For instance, colloidal silver can be formed through peptisation by adding small amounts of electrolyte to silver chloride.

Physical Chemistry

Physical chemistry bridges the gap between the physics that governs atomic and molecular behavior and the classic study of chemical reactions. It involves a lot of exploration into the mechanisms of how reactions occur and the conditions under which materials are stable or change.

In the context of colloid formation, the process involves understanding phase transitions at the microscopic level. The principles behind peptisation that drive colloids to form are deeply embedded in charges, intermolecular forces, and how substances interact on a level that we can't see with the naked eye.

Crucial Concepts

• Adsorption: In peptisation, this refers to the way ions adhere to the surface of solid particles.
• Charge Stabilization: Once the particles have an electric charge due to adsorption, they repel each other, keeping the system stable.
• Dispersion: This relates to how particles are distributed throughout the medium to form the colloid.

JEE Chemistry Problems

For students preparing for competitive exams like the Joint Entrance Examination (JEE) in India, understanding the concept of peptisation and colloid formation is important. JEE chemistry problems often test a student's grasp of core chemical processes and their ability to apply these concepts to a variety of questions.

High scoring students understand that concepts are interlinked. A firm grasp of physical chemistry fundamentals paves the way for solving real-world chemistry problems like those in the JEE. For success in the chemistry section of the JEE, focus on how physical chemistry connects to analytical, inorganic, and organic chemistry.

When tackling JEE chemistry problems, it's essential to read and thoroughly understand the question, dissect the terms, and apply conceptual knowledge to find the solution - much like how one would approach the problem of identifying the correct process of colloid formation from a suspension.