NCERT Solutions for Class 12 Chemistry Chapter 2 – Solutions

NCERT Solutions for Class 12 Chemistry Chapter 2 – Solutions have been drafted by our eminent Chemistry experts based on the latest CBSE syllabus. This chapter talks about all the essential concepts regarding properties of solutions helping you to understand its importance in real life. The chapter of NCERT Solutions gives you information about types of solution, how to determine the concentration of solutions, and distinguish between ideal and non-ideal solutions, Henry’s law and Raoult’s law. This also tells you about the very important property of solutions used in daily life, that is colligative properties.

There are a total of 41 questions asked at the end of the chapter covering all the concepts in NCERT CBSE Class 12 Chemistry Chapter 2. The questions given in the chapter enable you to practice the principles and facts to learn about solutions and their properties thoroughly. The frequently asked questions in board exams come from colligative properties and abnormal molar mass sections. 

All of these questions are answered comprehensively in Class 12 Chemistry Chapter 2 – Solutions. They follow all the guidelines given by CBSE and NCERT. These methodical solutions help you learn effectively and retain. They are exhaustive yet precise. They have been written in an easy to understand language and are fully accurate.

NCERT Class 12 Chemistry Chapter 2

NCERT Solutions for Class 12 Chemistry Chapter 2 – Solutions encompass all the important ideas and concepts given in the unit. They give you an in-depth understanding of the different concepts. Some concepts covered in this chapter have been given below.

  • Types of Solutions

This part of the chapter tells you that solutions having uniform composition and properties throughout are called homogeneous solutions. The solutions can be gaseous, liquid or solid depending upon the solvent (solute may be one out of gas, liquid or solid). 

  • Expressing the concentration of Solutions

This portion of the chapter is very important from a practical point of view as all the chemical reactions are based on its good knowledge and application. This portion teaches you the different forms of expressing the concentration of a solution. 

The common ones used are Molarity, Mass percentage (w/w), Mole fraction, Volume percentage (V/V), mass by volume percentage (w/V), and parts per million.

  • Solubility

This part of the chapter studies the effect of nature of solvent, solute and temperature on solubility

    • The solubility of a solid in liquid 

This portion of the chapter tells you that solubility of a solid is majorly affected by temperature and that pressure does not have any significant effect on solubility.

    • The solubility of a gas in a liquid

This part of the chapter discusses the famous Henry’s law, which, directs the dissolution of gas in liquids at a constant temperature. It states that solubility is directly proportional to the pressure of that gas over the liquid surface, and its most common form is p = KH x, where p is the partial pressure of the gas, x is the mole fraction of gas dissolved and KH is Henry’s constant. 

Henry’s law is applied immensely in industrial problems and in explaining biological phenomena. This chapter further tells you that solubility of gases in liquids decreases upon increasing temperature. 

  • Vapour Pressure of Liquid Solutions

This part of the chapter deals with properties of binary solutions, liquids in liquids and solids in liquids type.

    • Vapour pressure of liquid-liquid solutions

This part of the chapter conveys about the quantitative relationship between two components of a liquid-liquid solution, known as Raoult’s law.

    • Raoult’s law as a special case of Henry’s law

This part of the chapter teaches you that in a solution of a gas in a liquid, that is one of the components is gas, Raoult’s law can be compared to Henry’s law as a special case of latter. Here, KH becomes p1° which is the vapour pressure of pure component 1.

  • Vapour pressure of solutions of solids and liquids

This part of the NCERT CBSE Class 12 Chemistry Chapter 2 tells that vapour pressure of a mixture of a solid in a solvent is lower than the pure solvent, and the decrease in the vapour pressure is determined by the quantity of non-volatile solute present in solution. 

  • Ideal and Non-Ideal Solutions

In this portion of the chapter, you learn that on the basis of Raoult’s law, liquid-liquid solutions are divided into ideal and non-ideal solutions.

    • Ideal solutions

Here you come to know that ideal solutions obey Raoult’s law over the whole range of concentration. Two significant properties of ideal solutions are that their enthalpy and volume of mixing is zero – ΔmixH = 0 and ΔmixV = 0.

    • Non-ideal solutions

This part of the CBSE NCERT Class 12 Chemistry Chapter 2 tells you that non-ideal solutions do not obey Raoult’s law over the whole range of concentration. In case they show higher vapour pressure than predicted, it’s called a positive deviation. If they show lower vapour pressure than predicted by Raoult’s law, it’s called negative deviation. Nature of molecular interactions is the cause of this deviation. Azeotropes are a result of a large variation from Raoult’s law.

  • Colligative Properties and Determination of Molar Mass

This part of the chapter teaches you about colligative properties of solutions which depend upon the number of solute particles and are independent of their chemical nature. These are the different colligative properties – the relative lowering of vapour pressure, elevation of boiling point, depression of freezing point, osmosis and osmotic pressure. 

It further tells you that colligative properties are used for the determination of the molecular mass of solutes and derives and presents several expressions to calculate different parameters of solutions. 

  • Reverse osmosis and water purification

This part of NCERT Class 12 Chapter 2 tells that if a pressure higher than the osmotic pressure is applied on a solution, the process of osmosis can be reversed, and this is known as reverse osmosis. This principle is used to purify seawater for human consumption.

  • Abnormal Molar Masses

This part of the chapter teaches you that ionic compounds undergo dissociation into ions when dissolved in water and due to interionic interactions, some solutes particles can associate also. This brings abnormality in their observed molecular masses, being higher than actual in case of association and lower in case of dissociation. The Van’t Hoff factor i is the quantitative depiction of the extent to which association or dissociation has taken place.

CBSE NCERT Class 12 Chemistry Chapter 2 Exercise

Our NCERT Solutions for Chapter 2 – Solutions consists of 41 questions covering the important concepts learnt. The components of the exercise have been listed below. 

  • Questions 1 and 2 are direct questions based on types of solutions.
  • Questions 3 to 9 are direct and numerical questions based on knowledge and application of concentration depicting terms like molarity.
  • Questions 10, 11, 23, 24, 25 are application based questions on intermolecular forces.
  • Questions 12 and 13 are based on Henry’s law.
  • Questions 14 is a direct question based on deviation from Raoult’s law.
  • Question 15 asks you to determine the molar mass of the solute. 
  • Questions 16 to 19 are numerically asking you to determine molar mass/vapour pressure of a solution.
  • Questions 20 to 22 are numerical questions based on colligative properties.
  • Questions 26 to 30 are word problems based on concentration depicting terms like molarity. 
  • Questions 31 to 41 are word problems based on colligative properties and ask you to determine different parameters of the solutions.

This chapter of CBSE NCERT Class 12 Chapter 2 also contains 12 intext questions which have been answered systematically in our solutions.

Benefits of NCERT Solutions for Class 12th Chemistry Chapter 2 – Solutions

The important benefits of learning and revising from NCERT Solutions for Class 12 Chemistry Chapter 2 – Solutions are given below-

  • They help you become thorough with the fundamental concepts related to solutions and score more marks in your board exams.
  • They are to the point, fully accurate and facilitate speedy and effective learning.
  • They cover all concepts of the chapter in details and a step by step manner.
  • Our NCERT Solutions help you in fast leaning and revising during your board exams.
  • They also prepare you well to excel in various competitive exams. 
  • The solutions given let you understand the topics covered in the chapter in a better way while preparing you for scoring high in class 12th board exams.