NCERT Class 12 Chemistry Chemistry-I: Chapter 1 — Solutions
This chapter, "Solutions," from NCERT Class 12 Chemistry, introduces the concept of solutions as homogeneous mixtures. It explains that solutions consist of a solvent and one or more solutes, and can exist in gaseous, liquid, or solid states. The chapter emphasizes the importance of expressing solution concentration quantitatively, detailing methods like mass percentage (w/w) and volume percentage (V/V). It also outlines learning objectives including describing solution types, expressing concentration, understanding Henry's and Raoult's laws, distinguishing ideal and non-ideal solutions, explaining deviations, and describing colligative properties. This foundational knowledge is crucial for understanding chemical reactions and physical properties in various contexts, aiding CBSE students in their chemistry studies.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 12 |
| Subject | Chemistry |
| Book | Chemistry-I |
| Chapter | Chapter 1 — Solutions |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 3 minutes |
| Word count | 532 |
Learning outcomes
- Describe the formation of different types of solutions.
- Express the concentration of solutions in various units.
- State and explain Henry's law and Raoult's law.
- Distinguish between ideal and non-ideal solutions.
- Explain deviations of real solutions from Raoult's law.
- Describe colligative properties and their relation to molar masses.
Vocabulary
| Word | Meaning |
|---|---|
| Homogeneous mixture | A mixture whose composition and properties are uniform throughout. |
| Solvent | The component present in the largest quantity in a solution, which determines its physical state. |
| Solute | One or more components present in a solution other than the solvent. |
| Binary solution | A solution consisting of two components. |
| Concentration | A quantitative description of the amount of solute present in a solution. |
| Mass percentage (w/w) | The mass of the component per 100 units of total mass of the solution. |
| Volume percentage (V/V) | The volume of the component per 100 units of total volume of the solution. |
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Practice questions
- What is a homogeneous mixture? Answer: A homogeneous mixture is one where the composition and properties are uniform throughout.
- Define solvent and solute. Answer: The solvent is the component in the largest quantity, determining the physical state. Solutes are the other components present.
- What does 10% glucose in water by mass mean? Answer: It means 10 g of glucose is dissolved in 90 g of water, making a total of 100 g of solution.
Practice MCQs
Q1. Which of the following is a homogeneous mixture?
Explanation: Salt dissolved in water forms a homogeneous mixture because the salt particles are uniformly distributed throughout the water.
Q2. In a binary solution, the component present in the largest quantity is called the:
Explanation: By definition, the solvent is the component present in the largest amount in a solution.
Q3. If a solution has 20% ethanol by volume in water, what does it mean?
Explanation: Volume percentage (V/V) means 20 mL of ethanol is present in a total volume of 100 mL of solution.
Q4. Which of these is an example of a gaseous solution?
Explanation: A mixture of gases like oxygen and nitrogen is a homogeneous mixture where both components are in the gaseous state.
Q5. The concentration described by mass percentage is commonly used in:
Explanation: Mass percentage is frequently used in industrial settings for specifying the concentration of chemicals in commercial products.
Frequently asked questions
What is a solution in Chemistry?
A solution is a homogeneous mixture of two or more substances, where one substance (solute) is dissolved in another (solvent).
What are the main components of a solution?
A solution consists of a solvent, which is typically present in the larger amount, and one or more solutes, which are dissolved in the solvent.
What is the difference between mass percentage and volume percentage?
Mass percentage (w/w) expresses the mass of a component per 100 units of total mass of the solution, while volume percentage (V/V) expresses the volume of a component per 100 units of total volume of the solution.
What are the different states in which solutions can exist?
Solutions can exist in three states: gaseous (e.g., air), liquid (e.g., salt water), and solid (e.g., alloys).
Why is it important to express concentration quantitatively?
Quantitative descriptions of concentration, like mass percentage, avoid confusion and provide precise information needed for scientific and industrial applications.
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NCERT Class 12 Chemistry — Chemistry-I — Chapter 1 — Solutions. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.