NCERT Exemplar problems are the best source to practice the critical questions like Higher Order Thinking Skill (HOTS) questions. Every year, many questions from the NCERT Exemplar are directly asked in the board exams. Also, these are the kind of questions asked in the various competitive exams and Olympiad level tests. So, it’s very important for students to practice the NCERT exemplar problems to prepare well for the boards and the competitive exams.
NCERT Exemplar Solutions for Class 12 Chemistry chapter, Surface Chemistry:
In this article we are providing the precise solutions to all the NCERT Exemplar Problems for class 12 chapter- Surface Chemistry. All these solutions have been prepared by the subject matter experts. These solutions are designed in the most appropriate and the simplest way so as to help students easily understand the concepts and theories employed. This will help them make an easy preparation for the exams.
Few problems along with their solutions from this chapter are given follows:
Q. Extent of adsorption of adsorbate from solution phase increases with………
(a) increase in amount of adsorbate in solution
(b) decrease in surface area of adsorbent
(c) increase in temperature of solution
(d) decrease in amount of adsorbate in solution
Ans. (a) increase in amount of adsorbate in solution
Extent of adsorption of adsorbate from solution phase increases with increase in amount of adsorbate in solution. As amount of adsorbate in the solution increases, interaction of adsorbate with adsorbent also increases which leads to increase in extent of adsorption.
Q. Which of the following will show Tyndall effect?
(a) Aqueous solution of soap below critical micelle concentration
(b) Aqueous solution of soap above critical micelle concentration
(c) Aqueous solution of sodium chloride
(d) Aqueous solution of sugar
Ans. (b) Aqueous solution of soap above critical micelle concentration
Aqueous solution of soap above critical micelle concentration leads to formation of colloidal solution. Tyndall effect is a characteristic of colloidal solution in which colloidal particles show a coloured appearance when sunlight is passed through it and seen from the perpendicular side.
Q. Why is desorption important for a substance to act as good catalyst?
Ans. Desorption is important for a substance to act as a good catalyst so that after the reaction, the products formed on the surface separate out (desorbed) to create free surface again for other reactant molecules to approach the surface and react. If desorption does not occur then other reactants are left with no space on the catalysts surface for adsorption and reaction will stop.
Q. Assertion (A) Colloidal solutions show colligative properties.
Reason (R) Colloidal particles are large in size.
Ans. (b) Assertion and reason both are correct, but reason does not explain assertion.
Colloidal particles being bigger aggregates, the number of particles in a colloidal solution is comparatively small as compared to a true solution. Hence, the values of colligative properties (osmotic pressure, lowering in vapour pressure, depression in freezingpoint and elevation in boiling point) are of small order as compared to values shown by true solutions at same concentration.
Find below the links to download Class 12 Chemistry NCERT Exemplar Solutions for chapter 5- Surface Chemistry:
Link to Download Solutions
Multiple Choice Questions (Type-I)
Multiple Choice Questions (Type-II)
Short Answer Type Questions
Matching Columns Type Questions
Assertion and Reason Type Questions
Long answer types questions
Class 12 Chemistry NCERT Exemplar Problems: Surface Chemistry
NCERT Exemplar book for class 12 Chemostry consists of a collection of conceptual questions which are designed purely to check a student’s understanding about the various concepts and theories explained in the subject. These problems form the best practice source to prepare effectively for board exams and the medical entrance tests.
Important topics discussed in Class 12 Chemistry chapter – Surface Chemistry, are:
- Distinction between Adsorption and Absorption
- Mechanism of Adsorption
- Types of Adsorption
- Adsorption Isotherms
- Adsorption from Solution Phase
- Applications of Adsorption
- Homogeneous and Heterogeneous Catalysis
- Adsorption Theory of Heterogeneous Catalysis
- Shape-Selective Catalysis by Zeolites
- Enzyme Catalysis
- Catalysts in Industry
- Colloids and their Classification
- Preparation of Colloids
- Purification of Colloidal Solutions
- Properties of Colloidal Solutions
- Colloids Around Us.
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