The document explains the definition and properties of matter, which can exist in various states such as solid, liquid, gas, and plasma. It discusses the relationship between matter and energy, including the mass-energy equivalence principle, and classifies properties of matter into physical and chemical categories. Additionally, it covers techniques for the separation of mixtures, detailing methods like filtration, decantation, evaporation, distillation, and crystallization.

1. General Chemistry (Chem 1102)
Chapter 3
Matter and Change

2. Matter
Definition of Matter
 Matter refers to anything that occupies space and has mass.
 It is the physical substance that makes up the universe and all the
objects within it.
 Matter can exist in various forms, including solid, liquid, gas, or
plasma, and it is composed of tiny particles called atoms.

3.  Atoms are the building blocks of matter and consist of a nucleus, which contains
positively charged protons and neutral neutrons, as well as negatively charged
electrons that orbit the nucleus.
 The specific arrangement and combination of atoms determine the properties
and characteristics of different types of matter.

4. Energy
• Energy is a fundamental concept in physics that refers to the ability of a system to
do work or cause a change.
• It is a scalar quantity, meaning it has magnitude but no direction.
• Energy exists in various forms and can be transformed from one form to another.

5. The relationship between energy and matter:
• The relationship between matter and energy can e described by the famous
equation proposed by Albert Einstein, known as the mass-energy equivalence
principle or simply E=mc².
This equation states that energy (E) is equal to
the mass (m) of an object multiplied by the
square of the speed of light (c) in a vacuum.
In other words, mass and energy are
interchangeable and can be converted into each
other.

6. Properties of matter
• Properties of substances refer to the characteristics or attributes that can be used
to describe and identify them.
• These properties can be classified into two main categories:
I. Physical properties and
II. Chemical properties.

7. Physical properties
• Physical properties are those that can be observed or measured
without changing the chemical composition of the substance.

8. Examples of physical properties include:
Density: The mass of a substance per unit volume.
Melting point: The temperature at which a substance changes from a solid to
a liquid state.
Boiling point: The temperature at which a substance changes from a liquid to
a gaseous state.
Color: The visual appearance of a substance.
Odor: The characteristic smell of a substance.
Solubility: The ability of a substance to dissolve in a particular solvent.
Conductivity: The ability of a substance to conduct heat or electricity.
Hardness: The resistance of a substance to being scratched or dented.

9. Intensive and Extensive properties of matter:
 Intensive and extensive properties are classifications used to characterize
and describe different types of properties of matter.
Intensive Properties:
 Intensive properties are independent of the amount or size of the sample
being observed.
 These properties describe the inherent characteristics of a substance,
regardless of the quantity of the substance present.

10. Examples of intensive properties include:
Temperature: The measure of the average kinetic energy of particles in a substance.
Density: The mass per unit volume of a substance.
Color: The visual appearance of a substance.
Melting point: The temperature at which a substance changes from a solid to a liquid
state.
Boiling point: The temperature at which a substance changes from a liquid to a gaseous
state.
Refractive index: The extent to which light is bent when passing through a substance.
Specific heat capacity: The amount of heat energy required to raise the temperature of a
substance by a certain amount.

11. Examples of extensive properties include:
Mass: The amount of matter in a substance.
Volume: The amount of space occupied by a substance.
Total energy: The sum of all forms of energy (kinetic, potential, etc.)
possessed by a substance.
Total charge: The net electric charge of a substance.
Total heat capacity: The total amount of heat energy required to raise the
temperature of a substance by a certain amount.
Extensive Properties:
 Extensive properties depend on the amount or size of the sample being
observed.
 These properties change as the quantity of the substance changes.

12. Chemical Properties
• Chemical properties describe how a substance interacts or reacts with other
substances, leading to changes in its chemical composition.

13. Examples of chemical properties include:
Reactivity: The ability of a substance to undergo chemical reactions with other
substances.
Flammability: The tendency of a substance to burn or ignite in the presence of a flame.
Oxidation: The ability of a substance to react with oxygen, often resulting in the
formation of oxides.
pH: The measure of acidity or alkalinity of a substance.
Stability: The tendency of a substance to remain unchanged or undergo decomposition
over time.
Toxicity: The degree to which a substance can cause harm or toxicity to living
organisms.

14. States of matter
Matter is classified into different types based on its composition and
properties. The three main states of matter are: Solid, Liquid an Gas.
Solid:
 In this state, matter has a definite shape and volume.
 The particles in a solid are tightly packed together and vibrate in fixed
positions.

15. Liquid:
• Liquids have a definite volume but take the shape of their container.
• The particles in a liquid are close together but have more freedom to move and
flow past one another.

16. Gas:
• Gases have neither a definite shape nor a definite volume.
• The particles in a gas are widely spaced and move freely, colliding with each other
and the walls of the container.

17. • There is also a fourth state of matter called plasma, which is a highly ionized gas
consisting of charged particles.
• Plasma is commonly found in stars and other high-energy environments.

18. Changes in matter and energy
• Changes in matter and energy refer to the transformations and interactions that
occur within physical systems.
• Matter can undergo various changes, such as physical changes and chemical
changes, while energy can be transferred or transformed from one form to
another.

19.  Physical Changes:
Physical changes involve alterations in the physical state or properties of matter
without changing its chemical composition.
Examples of physical changes include:
changes in state (e.g., melting, freezing, vaporization, condensation),
changes in shape or size (e.g., cutting, grinding, crushing), and
changes in physical properties (e.g., changes in color, density, solubility) that
do not result in the formation of new substances.
Physical changes are usually reversible, meaning the original substance can be
recovered.
Changes in Matter:

21.  Chemical Changes:
Chemical changes, also known as chemical reactions, involve the transformation of one
or more substances into new substances with different chemical compositions.
Chemical changes typically involve the breaking and forming of chemical bonds.
Examples of chemical changes include:
combustion, oxidation, decomposition, and
various types of reactions, such as acid-base reactions and precipitation
reactions.
Chemical changes are usually accompanied by the release or absorption of energy.

23. Changes in Energy:
• Energy can undergo various changes, including transfer and transformation.
• Energy transfer refers to the movement of energy from one object or system to another
without any change in its form or type.
• Energy transformation involves the conversion of energy from one form to another.
• Forms of energy include kinetic energy (energy of motion), potential energy (energy
stored due to position or condition), thermal energy (heat energy), electromagnetic
energy (energy carried by electromagnetic waves), chemical energy (energy stored in
chemical bonds), and many others.

24. • Energy can be transferred and
transformed through various
processes, such as mechanical work,
heat transfer, electromagnetic
radiation, and chemical reactions.
• The law of conservation of energy
states that energy cannot be created
or destroyed; it can only be
transferred or transformed from one
form to another.

25. Classification of matter based on composition:
• Based on its composition matter can classified in to elements, compounds, and
mixtures.
Have a Constant
composition.
Have no a constant
composition

26. Elements:
• Elements are pure substances that cannot be chemically broken down into
simpler substances.
• Each element is made up of atoms with the same atomic number.
Examples of elements include:
Hydrogen (H), Oxygen (O), Carbon (C), and Gold (Au).
• Elements are listed on the periodic table, which arranges them based on their
atomic number.

27. Compounds:
• Compounds are substances composed of two or more different elements
chemically combined in fixed ratios.
• Compounds have properties distinct from those of their constituent elements.
Examples of compounds include:
Water (H2O), Carbon dioxide (CO2), and Sodium chloride (NaCl).

28. Mixtures:
• Mixtures are combinations of two or more substances that are physically
intermingled but not chemically bonded.
• The components of mixtures can be separated by physical means, such as
filtration, distillation, or evaporation.
Mixtures can be further classified into two types:
I. Homogeneous mixtures (solutions): Uniformly mixed throughout, with no
visible boundaries between the components.
Examples include saltwater and air.
II. Heterogeneous mixtures: Not uniformly mixed, with distinct visible
boundaries between the components.
Examples include salad dressing and granite.

29. Techniques of separation of components of mixtures
• Techniques of separation are used to isolate and purify the components of
mixtures by taking advantage of their different physical properties.
Filtration:
 Filtration is a method used to separate
solid particles from a liquid or gas by
passing the mixture through a porous
material called a filter.
 The filter allows the liquid or gas to pass
through while retaining the solid
particles.
 Filtration is commonly used to separate
suspended solids from liquids or to
remove solid impurities from a gas
stream.

30. Decantation:(kerera)
 Decantation is a process of separating a
mixture of solid particles and a liquid by
carefully pouring off the liquid, leaving
the solid particles behind.
 It is typically used when the solid
particles settle at the bottom of the
container due to their higher density or
gravity.
 Decantation is often used for separating
a mixture of solids and liquids that do
not form a homogeneous mixture.

31. Evaporation:
 Evaporation is a technique used to
separate a soluble solid from a liquid
by heating the mixture, causing the
liquid to vaporize and leaving behind
the solid.
 The liquid is heated until it reaches
its boiling point, and the vapor is
collected or allowed to escape,
leaving the solid residue.
 Evaporation is commonly employed
to obtain salts from their solutions or
to separate volatile components
from non-volatile substances.

32. Distillation:
 Distillation is a process that utilizes
differences in boiling points to
separate a mixture of liquids or a
liquid from a solution.
 The mixture is heated, and the
component with the lower boiling
point vaporizes first. The vapor is
then collected and condensed back
into a liquid.
 Distillation is often used to obtain
pure water from a saline solution
or to separate different
components of a mixture with
different boiling points, such as
ethanol from a fermented mixture.

33. Crystallization:
 Crystallization is a technique
used to separate a dissolved
solid from a liquid by cooling
the mixture, allowing the
solid to form crystals and
separate from the liquid.
 By controlling the cooling
rate and conditions, desired
crystals can be obtained.
 Crystallization is commonly
used to purify substances
and obtain highly pure solid
compounds.