1. Introduction
A solution is a homogeneous mixture of two or more substances. It consists of:
- Solute: The substance that dissolves
- Solvent: The substance in which the solute dissolves
Understanding solutions is important in daily life, chemistry, and industry.
2. Solute and Solvent
- Solute: Usually present in smaller amount
- Examples: Sugar in water, salt in water
- Solvent: Usually present in larger amount
- Examples: Water in sugar solution, water in salt solution
- Important Point: A solute can be solid, liquid, or gas. A solvent is often a liquid.
3. Types of Solutions
- Solid in Liquid: Salt in water, sugar in water
- Gas in Liquid: Carbon dioxide in soda
- Liquid in Liquid: Alcohol in water
- Gas in Gas: Air (oxygen in nitrogen)
- Solid in Solid: Alloys like brass (zinc in copper)
4. Concentration of Solutions
- Concentrated Solution: Large amount of solute dissolved in solvent
- Dilute Solution: Small amount of solute dissolved in solvent
- Saturated Solution: Maximum solute dissolved at a given temperature
- Unsaturated Solution: Less solute than maximum dissolved
- Supersaturated Solution: More solute than normally possible (unstable)
5. Factors Affecting Solubility
- Nature of solute and solvent – “Like dissolves like” (polar substances dissolve in polar solvents)
- Temperature – Solubility of solids usually increases with temperature; gases decrease with temperature
- Pressure – Affects solubility of gases (e.g., carbonated drinks under pressure)
6. Methods of Separation of Solutions
- Evaporation: Separate dissolved solids from liquids
- Distillation: Separate liquid from solute or other liquids
- Chromatography: Separate colored solutes in solution
- Filtration: For heterogeneous mixtures (insoluble solids)
7. Properties of Solutions
- Homogeneous
- Transparent (in most cases)
- Solute cannot be separated by filtration
- Solubility varies with temperature and pressure
8. Key Terms
| Term | Meaning |
|---|---|
| Solute | Substance that dissolves in a solvent |
| Solvent | Substance in which solute dissolves |
| Solution | Homogeneous mixture of solute and solvent |
| Saturated | Solution with maximum solute dissolved |
| Unsaturated | Solution with less than maximum solute |
| Supersaturated | Solution with more solute than normally soluble |
| Concentrated | Large amount of solute dissolved |
| Dilute | Small amount of solute dissolved |
| Solubility | Maximum amount of solute that can dissolve at a given temperature |
9. Examples in Daily Life
- Tea or coffee → Solid in liquid
- Soda → Gas in liquid
- Air → Gas in gas
- Brass → Solid in solid
- Vinegar → Liquid in liquid
10. Possible Questions
Very Short Answer Questions (1–2 marks)
- Define solute and solvent.
- Give one example of gas in liquid solution.
- What is a saturated solution?
- Name a liquid-liquid solution.
- Give an example of solid-solid solution.
Short Answer Questions (3–5 marks)
- Differentiate between concentrated and dilute solutions.
- Explain saturated, unsaturated, and supersaturated solutions.
- List factors affecting solubility.
- Describe methods of separating solute from solvent.
Long Answer Questions (6–8 marks)
- Explain the nature of solutions with examples of different types.
- Discuss how temperature and pressure affect solubility.
- Explain the separation of a soluble solid from its solution using suitable methods.
- Describe “like dissolves like” principle with examples.
Multiple Choice Questions (MCQs)
- Water is a:
a) Solute
b) Solvent
c) Solution
d) Mixture
Answer: b - Salt in water forms:
a) Homogeneous mixture
b) Heterogeneous mixture
c) Compound
d) Element
Answer: a - Supersaturated solution is:
a) Unstable
b) Stable
c) Homogeneous
d) Heterogeneous
Answer: a
Fill in the Blanks
- Solution is a homogeneous mixture.
- Carbon dioxide in soda is gas in liquid solution.
- Solubility of gases decreases with increase in temperature.
True/False Questions
- Filtration can separate solute from a solution. False
- Brass is a solid-solid solution. True
- Saturated solution can dissolve more solute at a given temperature. False
Match the Following
| Column A | Column B |
|---|---|
| Solute | Sugar in tea |
| Solvent | Water in tea |
| Gas in liquid | Carbon dioxide in soda |
| Liquid in liquid | Alcohol in water |
| Solid in solid | Brass |
Basic Concepts
- A solution is a:
a) Heterogeneous mixture
b) Homogeneous mixture
c) Compound
d) Element
Answer: b - The substance that dissolves is called:
a) Solvent
b) Solute
c) Solution
d) Mixture
Answer: b - The substance in which solute dissolves is called:
a) Solute
b) Solvent
c) Solution
d) Compound
Answer: b - Sugar in water forms:
a) Solute
b) Solvent
c) Solution
d) Mixture
Answer: c - Air is an example of:
a) Gas in gas solution
b) Liquid in liquid solution
c) Solid in liquid solution
d) Gas in liquid solution
Answer: a
Types of Solutions
- Salt in water is an example of:
a) Gas in gas
b) Solid in liquid
c) Liquid in liquid
d) Solid in solid
Answer: b - Alcohol in water is an example of:
a) Solid in liquid
b) Liquid in liquid
c) Gas in liquid
d) Gas in gas
Answer: b - Carbon dioxide in soda is an example of:
a) Solid in liquid
b) Liquid in liquid
c) Gas in liquid
d) Gas in gas
Answer: c - Brass is an example of:
a) Solid-solid solution
b) Gas-liquid solution
c) Liquid-liquid solution
d) Gas-solid solution
Answer: a - Vinegar is a:
a) Solid-solid solution
b) Liquid-liquid solution
c) Gas-liquid solution
d) Gas-gas solution
Answer: b - Air is a mixture of:
a) Oxygen in nitrogen
b) Nitrogen in oxygen
c) Both a and b
d) Only oxygen
Answer: c - A homogeneous mixture has:
a) Uniform composition
b) Non-uniform composition
c) Only solids
d) Only liquids
Answer: a - A heterogeneous mixture has:
a) Uniform composition
b) Non-uniform composition
c) Only liquids
d) Only gases
Answer: b - Salt + sugar forms:
a) Solution
b) Mixture
c) Compound
d) Element
Answer: b - Which of these is a liquid-liquid solution?
a) Alcohol + water
b) Salt + water
c) Air
d) Brass
Answer: a
Concentration of Solutions
- A solution with a large amount of solute is called:
a) Dilute
b) Concentrated
c) Unsaturated
d) Supersaturated
Answer: b - A solution with a small amount of solute is called:
a) Concentrated
b) Dilute
c) Saturated
d) Supersaturated
Answer: b - A solution that cannot dissolve any more solute at a given temperature is:
a) Unsaturated
b) Saturated
c) Dilute
d) Supersaturated
Answer: b - A solution with more solute than normally possible is:
a) Saturated
b) Dilute
c) Supersaturated
d) Unsaturated
Answer: c - Unsaturated solution:
a) Dissolves maximum solute
b) Dissolves less than maximum solute
c) Dissolves more than maximum solute
d) Cannot dissolve solute
Answer: b - Solubility of solid in liquid usually:
a) Increases with temperature
b) Decreases with temperature
c) Remains constant
d) Varies randomly
Answer: a - Solubility of gas in liquid:
a) Increases with temperature
b) Decreases with temperature
c) Remains constant
d) Increases with volume
Answer: b - “Like dissolves like” means:
a) Polar solute dissolves in polar solvent
b) Non-polar solute dissolves in polar solvent
c) Gas dissolves in gas
d) Liquid dissolves in solid
Answer: a - Sugar in water is an example of:
a) Polar solute in polar solvent
b) Non-polar solute in polar solvent
c) Polar solute in non-polar solvent
d) Non-polar solute in non-polar solvent
Answer: a - Oil does not dissolve in water because:
a) Both are polar
b) Both are non-polar
c) Oil is non-polar and water is polar
d) Oil is polar and water is non-polar
Answer: c
Separation of Solutions
- Evaporation is used to:
a) Separate dissolved solids from liquid
b) Separate two liquids
c) Separate solids from solids
d) Separate gases from liquids
Answer: a - Distillation is used to:
a) Separate dissolved solids from liquid
b) Separate liquids with different boiling points
c) Separate solids from solids
d) Separate gases from liquids
Answer: b - Filtration is used to separate:
a) Soluble solids
b) Insoluble solids
c) Liquids
d) Gases
Answer: b - Chromatography is used to:
a) Separate colored substances in solution
b) Separate solid from liquid
c) Separate gases
d) Separate liquids with different boiling points
Answer: a - Magnetic separation is used to separate:
a) Soluble solids
b) Magnetic substances
c) Liquids
d) Gases
Answer: b
Examples in Daily Life
- Tea or coffee:
a) Gas in liquid
b) Solid in liquid
c) Liquid in liquid
d) Solid in solid
Answer: b - Carbonated drinks:
a) Gas in liquid
b) Liquid in liquid
c) Solid in liquid
d) Gas in gas
Answer: a - Brass:
a) Solid-solid solution
b) Solid-liquid solution
c) Liquid-liquid solution
d) Gas-liquid solution
Answer: a - Air:
a) Gas in gas
b) Gas in liquid
c) Solid in liquid
d) Liquid in liquid
Answer: a - Vinegar:
a) Solid-liquid solution
b) Liquid-liquid solution
c) Gas-liquid solution
d) Solid-solid solution
Answer: b - Sugar solution:
a) Saturated solution
b) Unsaturated solution
c) Can be either depending on concentration
d) Cannot exist
Answer: c - Solubility of salt increases with:
a) Decrease in temperature
b) Increase in temperature
c) Pressure only
d) Volume only
Answer: b - Carbon dioxide in soda is:
a) Less soluble under pressure
b) More soluble under pressure
c) Unaffected by pressure
d) Insoluble
Answer: b - A supersaturated solution is:
a) Stable
b) Unstable
c) Cannot exist
d) Solid only
Answer: b - Water is called the universal solvent because:
a) Dissolves only polar solutes
b) Dissolves many substances
c) Dissolves gases only
d) Dissolves solids only
Answer: b
True/False
- Solute dissolves in solvent. True
- Evaporation can separate all solutions. False
- Supersaturated solutions are unstable. True
- Distillation separates solutes without heating. False
- Solubility of gases increases with temperature. False
Fill in the Blanks
- Solution is a homogeneous mixture.
- Solvent is usually present in larger amount.
- Saturated solution cannot dissolve more solute.
- “Like dissolves like” principle applies to polar and non-polar substances.
- Carbon dioxide in soda is gas in liquid solution.