SOLUTION

Q6: Define Solution, and also write down its properties.

Solutions

Definition:

A solution is a mixture where one substance dissolves in another. It looks the same throughout.

Examples:

Saltwater
Sugar water
Vinegar
Metal alloys like brass
Air

Properties of a Solution:

A solution is completely mixed and looks uniform.
The solute particles are tiny, smaller than 1 nm.
You cannot see the particles, even with a microscope.
A solution passes through filter paper, so it cannot be filtered.
Solutions stay mixed and do not separate over time.
They do not scatter light because the particles are very small.

Q7: What are the components of solution and write its properties.

Understanding Solutions

A solution is a uniform mixture of two or more substances. It has two main parts:

Components of a Solution

Solute: The substance that dissolves. It is present in a smaller amount.
Solvent: The substance that dissolves the solute. It is present in a larger amount.

Examples

In a salt solution, salt is the solute and water is the solvent. Some solutions have multiple solutes, like soft drinks. Here, water is the solvent, and sugar, salts, and CO₂ are solutes. Air is another example, where nitrogen is the solvent, and oxygen, carbon dioxide, and other gases are solutes.

Types of Solutions

Solutions exist in different physical states based on the state of the solvent.

Gaseous Solutions

These have a gas as the solvent. The Haber's process uses a mixture of nitrogen and hydrogen to produce ammonia. Other examples include:

Fog, clouds, and mist (water droplets in air)
Smoke (carbon particles in air)

Liquid Solutions

Here, the solvent is a liquid. Examples include:

Carbonated drinks (water as solvent, CO₂ as solute)
Vinegar (acetic acid in water)
Brine and sugar solutions (salt or sugar in water)

Solid Solutions

In solid solutions, the solvent is solid. Examples include:

Hydrogen gas absorbed by nickel (used in the ghee industry)
Amalgams (metals dissolved in liquid mercury)
Alloys (mixtures of metals like brass, bronze, and steel)

Q8: Write classification of solution in detail

Classification of Solutions

1. Based on Solvent Nature

Solutions are classified by the type of solvent used.

Aqueous Solutions

These solutions use water as the solvent.

Example: Salt in water, sugar in water.

Water is called the universal solvent because it dissolves many substances.

Non-Aqueous Solutions

These solutions use solvents other than water, such as alcohol or ammonia.

Example: Sugar dissolved in alcohol.

2. Based on Solubility

Saturated Solutions

These contain the maximum solute that can dissolve at a given temperature.

If more solute is added, it won’t dissolve.

Example: A sugar solution with the maximum sugar dissolved.

Unsaturated Solutions

These have less solute than they can hold. More solute can still dissolve.

Example: A sugar solution that can still dissolve more sugar.

Supersaturated Solutions

These hold more solute than a saturated solution. They are unstable.

Formed by heating a solution, dissolving excess solute, and cooling it slowly.

Example: A sugar solution that, when cooled, forms sugar crystals.

3. Based on Solute Quantity

Concentrated Solutions

Contain a high amount of solute relative to the solvent.

Example: 90% sugar, 10% water.

Dilute Solutions

Contain a low amount of solute relative to the solvent.

Example: 10% sugar, 90% water.

Q9: Define Solubility. What are the factors which affect solubility?

Solubility

Definition

Solubility is the maximum amount of a substance that can dissolve in 100 grams of a solvent at a given temperature.

If the solvent is water, solubility refers to how much of a substance can dissolve in 100 grams of water at a specific temperature.

Factors Affecting Solubility

Solubility depends on the type of solvent, temperature, and pressure.

Effect of Temperature on Solubility

Solids in Liquids

Most solids dissolve better in hot liquids. Heat gives energy to molecules, helping them break apart and mix into the liquid.

Example: Sugar dissolves better in hot water.

Exception: Some solids dissolve less in hot water. Example: Calcium sulfate.

Liquids in Liquids

Temperature has little effect on liquid-to-liquid solubility because both are already in the same phase.

Example: Ethanol and water mix well at all temperatures.

Gases in Liquids

Gases dissolve less in warm liquids. Higher temperature makes gas molecules move faster and escape.

Example: Soda loses fizz faster in warm temperatures.

Solubility of Some Salts

Solute	At 20°C	At 100°C
NaCl	36.5g	39.2g
KCl	37.5g	77g
Ca(OH)₂	0.173g	0.066g

Example: Calcium hydroxide dissolves less in hot water.

5. Describe the factors that influence the solubility of a substance, with a specific focus on the effect of temperature.

Factors Affecting Solubility

Solute & Solvent Nature: Substances dissolve best in similar types of solvents. Polar dissolves polar, non-polar dissolves non-polar.
Temperature: Higher temperatures usually help solids dissolve faster in liquids. However, gases dissolve less as temperature rises.
Pressure: This mostly affects gases. More pressure means more gas dissolves in liquids.
Stirring: Mixing speeds up the dissolving process by spreading solute particles evenly.

6 . If you have a saturated solution of sugar in water, what will happen if you increase the temperature and why?

Understanding Matter

When you heat a saturated sugar solution, more sugar dissolves. This is because higher temperature breaks forces between molecules, allowing more sugar to mix in.

Key Points

Matter: Anything with mass that takes up space.
Plasma: A charged gas affected by electric and magnetic fields.
Allotropy: An element’s ability to exist in different forms.
Element: The simplest matter, made of identical atoms.
Compound: A substance with two or more different atoms bonded together.
Solution: A uniform mixture of two or more substances.
Aqueous Solution: A solution where water is the solvent.
Saturated Solution: A solution that holds the maximum solute at a given temperature.
Unsaturated Solution: A solution with less solute than a saturated one.
Colloid: A mixture with particles between 1 and 1000 nanometers.
Suspension: A mix where solid particles float but don’t dissolve.

Study Resources

Students preparing for FBISE exams can refer to both NBF and Cantab books. These resources ensure comprehensive learning and help in SLO-based exam preparation.

Solution

I. Solution

A. Definition

Homogeneous mixture of two or more substances.

B. Key characteristics:

1. One substance dissolved in another
2. No visible particles of different substances
3. Uniform appearance

C. Components:

1. Solute: Substance that is dissolved
2. Solvent: Substance in which solute is dissolved

D. Particle size:

Microscopic ( 1 nm in diameter).

E. Stability:

Very stable, solute doesn't separate from solvent.

II. Types of Solutions (based on physical states)

A. Gaseous solutions
B. Liquid solutions
C. Solid solutions

III. Gaseous Solutions

A. Solvent:

Gas.

B. Solute:

Can be gas, liquid, or solid.

C. Examples:

1. Mixture of nitrogen and hydrogen (Haber's process)
2. Mixture of ammonia and carbon dioxide (urea preparation)
3. Fog, clouds, mist (liquid water in air)
4. Smoke (carbon particles in air)

IV. Liquid Solutions

A. Examples:

1. Carbonated drinks (gaseous CO₂ in liquid water)
2. Rectified spirit (liquid in liquid)
3. Vinegar (acetic acid in water)
4. Brine (solid salt in water)
5. Sugar syrup (solid sugar in water)

V. Solid Solutions

A. Examples:

1. Hydrogen gas on nickel metal surface (used in ghee industry)
2. Amalgam (metal dissolved in liquid mercury)
3. Alloys (mixture of different metals)
a. Brass
b. Bronze
c. Steel

VI. Real-life Examples

A. Air: Gaseous solution (N₂ solvent; O₂, CO₂, trace gases as solutes)
B. Seawater: Liquid solution
C. Alloy: Solid solution

Aqueous Solutions

I. Aqueous Solutions

A. Definition

Solution formed by dissolving a substance in water.

B. Characteristics:

1. Can contain dissolved solids, gases, or liquids
2. Must be stable to be a true solution

C. Examples:

1. Sugar in water
2. Table salt in water

D. Water as a universal solvent

Water is known as a universal solvent because it can dissolve many substances.

E. Common use:

Laboratories

Saturated Solution

Types of Solutions Based on Concentration

II. Types of Solutions Based on Concentration

A. Saturated Solution

1. Definition: Contains maximum amount of solute at a given temperature
2. Characteristics:
- a. No more solute can dissolve
- b. Undissolved solute in equilibrium with dissolved solute
- c. Dynamic equilibrium established

B. Unsaturated Solution

1. Definition: Contains less solute than required for saturation
2. Characteristic: Can dissolve more solute

C. Supersaturated Solution

1. Definition: Contains more solute than a saturated solution
2. Characteristics:
- a. Unstable
- b. Prepared by cooling a saturated solution from high temperature
3. Identification: Crystallization occurs when seed crystal is added

Solution Properties

Solubility Table

Solute	Solubility (Amount of solute in 100g of solvent at 20°C)	Solubility (Amount of solute in 100g of solvent at 100°C)
NaCl	36.5g/100g H₂O	39.2g/100g H₂O
KCl	24.7g/100g H₂O	56g/100g H₂O
NH₂Cl	37.5g/100g H₂O	77g/100g H₂O
Ca(OH)₂	0.173g/100g H₂O	0.066g/100g H₂O

Types of Solutions and Solubility

D. Concentrated and Dilute Solutions

1. Dilute: Relatively small amount of dissolved solute
2. Concentrated: Relatively large amount of dissolved solute
3. Example: Brine (concentrated salt solution)

III. Solubility

A. Definition: Maximum amount of solute that dissolves in a specified amount of solvent at a specific temperature
B. Factors affecting solubility:
- 1. Solvent used
- 2. Temperature
- 3. Pressure

IV. Effect of Temperature on Solubility

A. Increase in solubility with temperature (e.g., KCl, NH₄Cl)
B. Decrease in solubility with temperature (e.g., Ca(OH)₂)
C. No change in solubility with temperature (e.g., NaCl)

V. Activity: Demonstrating Types of Solutions

A. Unsaturated solution: Sugar dissolves in water
B. Saturated solution: Sugar stops dissolving at a certain point
C. Supersaturated solution: More sugar dissolves upon heating