Xam Idea Class 12 Chemistry Chapter 5 Solutions: Surface Chemistry

Our well structured and strategic Xam Idea Class 12 Chemistry Solutions Chapter 5 – Surface Chemistry is the best study material available on this topic of Surface chemistry. They follow the latest guidelines issued by CBSE and NCERT. Our best team of chemistry teachers have methodically and logically prepared these solutions to help boost your exam preparation.

Part A of Xam Idea Class 12 Chemistry Solutions Chapter 5 contains a detailed discussion of all concepts of the chapter. It comprises very short answer questions, short answer type questions and long answer type questions. These questions test your memory skills, analytical skills and higher-order thinking skills. Part B of our comprehensive solutions contains detailed answers to model papers based on CBSE board exam format and previous years question papers. All of this helps you to practice all the concepts learnt in this chapter holistically and become thorough with the same.

This chapter is based on the interfacial phenomenon shown by solutions and solids. Here you learn about types and mechanisms of adsorption, the factors controlling adsorption on solids, Freundlich’s adsorption isotherm, the role of catalysts in industry. Next, you learn about colloidal solutions, their preparation methods, their properties and use of colloids. Our solutions are written in simple language to help you grasp even the most complex topics easily.

Xam Idea Class 12 Chemistry Chapter 5 Overview

Our solutions cover all the topics and concepts given in this chapter of surface chemistry. Our solutions are a complete and holistic guide on this topic. They make learning an easy and fast process. They give you an in-depth understanding of the subject matter. The components of the chapter have been explained below.

  • Adsorption

This chapter introduces you to adsorption, which is a phenomenon of attracting and retaining the molecules of a gaseous or liquid substance on the surface of the adsorbent, resulting in a higher surface concentration compared to bulk. This happens due to the difference in forces acting upon the particles in the surface and particles in bulk. Here you will also learn that the material adsorbed is known as adsorbate, and one which adsorbs is called adsorbent. Xam Idea Class 12 Chemistry Solutions Chapter 5 – Surface Chemistry prepares you well for the Class 12 exams.

Further, you come to know about types of adsorption that are physisorption and chemisorption. Physisorption occurs due to weak van der Waals forces between adsorbate and adsorbent surface and chemisorption is a result of strong chemical bond formation between the molecules of adsorbate and adsorbent. You also come to know about different characteristics of physisorption and chemisorption and the main point of difference between them, the most important of which is the reversibility of physical adsorption.

  • Adsorption Isotherms

This portion of the chapter tells you that adsorption isotherm is a curve which expresses how the quantity of gas adsorbed by the adsorbent varies with change in pressure at a constant temperature. You learn here about Freundlich’s adsorption isotherm x/m = k.p1/n (n >1), where x is the amount of the gas adsorbed on mass m of the adsorbent at pressure p. The validity of Freundlich’s isotherm is obtained by plotting x/m on x and log p on the y-axis to obtain a straight line. Xam Idea Solutions Chapter 5 – Surface Chemistry teaches you simple tips and techniques for solving numerical questions.

This portion further tells that solids absorb solutes from solution phase also where it has been observed that extent of adsorption – decreases with increase in temperature and increases with the increase of surface area and depends on the concentration of solute in solution and nature of adsorbate and adsorbent used. Here, you also learn about the various applications of adsorption phenomena in various areas like industrial productions, metallurgy, chromatographic separations, among others.


  • Catalysis


This part of the chapter tells you that catalysts are those substances which, when added to a reaction mixture, help by increasing the rate of chemical reactions. Use of the catalysis process is widespread in many industries. You further come to know that catalysis can be of two types, homogeneous and heterogeneous catalysis. When the catalyst is in the same phase as of reactants, it is known as homogeneous catalysis. Heterogeneous catalysis is the case where catalysts and reactants are in different phases. This section also teaches you that catalytic reactions which depend upon the pore structure of the catalyst, and size of product and reactant molecules are known as shape-selective catalysis.


  • Adsorption theory of heterogeneous catalysis


This part of the chapter is about the mechanism of heterogeneous catalysis. You learn about the old and modern theories used for explaining the mechanism of heterogeneous catalysis. You learn here that according to modern adsorption theory the mechanism has following steps – diffusion of reactants to the surface of catalyst followed by adsorption of reactants and occurrence of chemical reaction on the catalyst surface and finally desorption of products from the catalytic surface and they’re moving away. Catalysts find a large utility in various industries.

Further, you learn about enzyme catalysis. This part of the chapter tells you that enzymes are complex organic compounds containing nitrogen elements and produced by plants and animals. Here you will learn that these are protein molecules catalyzing biochemical reactions. Enzyme catalysis is unique in being highly specific and efficient. Our effective Xam Idea Class 12 Chemistry Solutions Chapter 5 – Surface Chemistry explains all the concepts in a stepwise and precise manner and helps you prepare the chapter well from exam point of view.


  • Colloids


In this part of the chapter, you come to know about heterogeneous systems, where particles of finely dispersed substance (dispersed phase) are present in the dispersion medium, are known as colloidal systems or colloids. Colloidal solutions are midway between true solutions and suspensions.

Further, this chapter tells you about the classification of colloids. Colloids can be divided on the basis of the following criteria – physical state of the mediums, nature of the interaction between the mediums and type of particles of the dispersed phase. Here you will learn that the most common types are sols (solids in liquids), gels (liquids in solids) and emulsions (liquids in liquids). Our Xam Idea Class 12 Chemistry Solutions Chapter 5 – Surface Chemistry helps you delve deep into the concepts and strengthen your understanding of the topics.

This chapter also tells you about the preparation and purification of colloids. You learn here that colloidal solutions can be prepared by chemical, electrical and peptization methods. Here you will also learn that purification of colloidal solutions can be done by using the methods of dialysis, electrodialysis and ultrafiltration.

Next, you learn about the properties of colloidal solutions. The colloidal solutions show various properties due to the presence of particles in them. Colligative properties, Tyndall effect, Brownian movement, the charge on particles, the colour of colloidal solution, electrophoresis and coagulation are the common properties shown by them.


  • Emulsions


This portion of the chapter teaches you that emulsions are also colloidal systems. In emulsions, both dispersed phase and dispersion medium are liquids and can be of either water in oil type or oil in water type. The process of preparing emulsion is known as emulsification, and an emulsifier is added to ensure the stability of an emulsion.

Next, you learn about the predominant colloidal systems around us. You get to know various examples of colloids observed in daily life and application of colloids in industry. Our smart Xam Idea Class 12 Chemistry Solutions Chapter 5 – Surface Chemistry explains these principles in detail and helps you to lay a strong foundation of all the concepts.

Xam Idea Class 12 Chemistry Chapter 5 – Exercises

Part A of our Xam Idea Class 12 Chemistry Solutions Chapter 5 comprises detailed conceptual explanations and various question types such as very short answer questions (VSAQ) and short answer questions (SAQ) and long answer questions (LAQ). All of these have different marks allotted to them. Some other question types include multiple-choice questions, direct questions, fill in the blanks questions, value-based and description-based type questions. These test your analytical abilities, memory and higher-order thinking skills.

This chapter has 63 VSAQs on types of adsorption, factors affecting adsorption, adsorption isotherm, the role of adsorption in heterogeneous catalysis, examples of heterogeneous catalysis and some are based on colloids, based on enzymes, based on features of zeolite catalysis and shape-selective catalysis. There are 39 SAQs which ask you to distinguish between adsorption and absorption, adsorption isotherm, activation of adsorbent, why adsorption releases heat, various properties of colloidal solutions, emulsions, activity and selectivity of catalysis, micelles, and sols. 

Our Xam Idea Class 12 Chemistry Solutions Chapter 5 – Surface Chemistry includes detailed explanations for all the questions. They provide you with relevant examples to help you learn efficiently. Part B of our Xam Idea Class 12 Chemistry Solutions Chapter 5 consists extensive yet to the point solutions to various specimen papers, model questions papers, previous year question papers and other exemplar questions. After going through the questions given in Part A, it is advised that you also attempt the question papers in Part B to perfect your preparation.

Benefits of Xam Idea Class 12 Chemistry Chapter 5 – Surface Chemistry

The process of learning and revising from Xam Idea Class 12 Chemistry Solutions Chapter 5 – Surface Chemistry is highly beneficial for you. Some of the advantages are as follows –

  • They are easy to understand as they are written in a simple language.
  • They are all-encompassing yet to the point solutions providing the best way to remember the concepts of surface chemistry.
  • They are a hundred per cent accurate and reliable.
  • They make the process of learning interesting and efficient and ensure appropriate application of the topics learnt. 
  • They help you to achieve higher marks in Class 12 board exams and prepare well for the competitive exams.