Structure 1.1 Models of the particular nature and states of matters (1).pdf

IB DP chemistry notes Structure 1.1 by Anoosha Qaisar

1. Lecture notes
By
Ms. Anoosha Qaisar

2. TOPIC STRUCTURE 1: MODELS OF THE
PARTICULATE NATURE OF MATTER

3. Three states of Matter

5. CLASSIFYING THE MATTER
1 substance 2 or more substances
No fixed ratio
2 or more
elements in
fixed ratio
Chemically bonded Not chemically bonded

6. ELEMENTS
They are the simplest forms of matter and consist of only one type of atom. For this reason,
elements cannot be broken down chemically into simpler substances.
A list of all known elements can be found on the periodic table. There are 92 naturally occurring
elements with 26 synthesized. The most recent in (Nh) Nihonium in 2000.
Elements can exist as individual atoms, or they can exist as atoms of the same element bonded
together.The following examples are elements that are always found in nature to exist
bonded together as molecules, rather than as individual atoms. These can be diatomic
elements (formed by two atoms of the same element bonded together) or polyatomic
elements (more than two atoms of the same element bonded together).
Examples of the diatomic elements are: hydrogen (H2), nitrogen (N2), oxygen (O2),
fluorine (F2), chlorine (Cl2), bromine (Br2) and iodine (I2).
Examples of polyatomic elements are: phosphorus (P4) and sulfur (S8).

8. COMPOUNDS
Compounds are pure substances composed of two or more different elements chemically combined in fixed
ratios.Carbon (symbol C) is an element that forms millions of different compounds and even has its own
branch of chemistry dedicated to it, known as organic chemistry. The atoms in a compound are chemically
bonded to one another so they cannot be separated using physical methods. The properties of compounds
are different from the elements they contain.The structure of a compound depends on the type of bonding
between its atoms.Methane is made of two different elements, carbon and hydrogen (symbol H), chemically
bonded in fixed ratios (Figure 3). For every one carbon atom in a molecule of methane, there are four
hydrogen atoms.
Examples of compounds:

9. Another example of a compound is water, which has the molecular formula H2O.
Water is composed of hydrogen and oxygen atoms in a 2:1 ratio.
The ball and stick model for water, H2O.


The atoms in a compound are chemically bonded to one another so they cannot be separated using physical methods. The
properties of compounds are quite different from the elements they contain.
This point is illustrated in the reaction between the elements sodium and chlorine to produce the compound sodium chloride
(NaCl). Sodium is a very reactive metal that reacts vigorously with water. Chlorine is a toxic gas that is used to kill bacteria in
water treatment. The compound sodium chloride is a relatively safe substance that has been used for centuries to flavour food. The
properties of sodium chloride are very different from the elements that it is made from.

10. Drag and drop each of these substances into the correct column in Interactive activity.

11. MIXTURES
●Mixtures are composed of two or more elements or compounds in no fixed
ratio.
●Components of the mixtures are not chemically bonded so they can be
separated by physical methods.
●The components of a mixture retain their individual properties. We can use
methods to separate components according to their properties.
●For example salt, water , air , dirt etc
Heterogeneous
visible phases or boundaries
Non uniform (different parts of the
mixture have a different
composition).carbonated water, which
has bubbles of gaseous carbon dioxide
mixed with water or the mixture of
iron and sulfur. Mixture of water and
oil.

Homogeneous
do not have visible phases or boundaries
Uniform composition(equally distributed,same
state) eg. air that we breathe. The components
of air such as gaseous nitrogen, oxygen and
argon are evenly mixed resulting in a uniform
composition. salt water.
Interactive activity + questions

12. SEPARATION TECNIQUES
1.Filtration
2.Evaporation
3.Solvation
4.Distillation
5.Paper chromatography
6.Recrystallisation

13. FILTRATION
Filtration involves the separation of an insoluble solid from a liquid or solution.An
example would be the separation of a mixture of sand and water, which is a heterogeneous
mixture (Figure 1). The mixture of sand and water is poured through a piece of filter paper
held in a filter funnel. The sand is not dissolved in the water and cannot pass through the
pores in the filter paper. The water, known as the filtrate, is able to pass through the pores
and is collected in the beaker. The sand, known as the residue, remains in the filter paper
and can be collected.
Examples?

Figure 1

14. EVAPORATION
Evaporation is a separation technique used to separate a homogeneous mixture.An
example of this is salt water, a homogeneous mixture. The mixture of salt and water is heated, and the
water evaporates, leaving the salt behind. (Figure 2).
Figure 2

15. SOLVATION
Solvation involves the separation of a heterogeneous mixture of two solids based on differences
in solubility if one of the substances is soluble in a solvent, but the other solid is insoluble.The
insoluble solid can now be separated by filtration. The soluble substance can be separated from
the solution by evaporation.
FILTRATION + EVAPORATION

16. DISTILLATION
Distillation involves the separation of a liquid
mixture based on the difference in volatility or
boiling points between the components of the
mixture. An example is ethanol and water.
Each liquid has a different boiling point; water
boils at 100 °C and ethanol at 78 °C.Each
liquid has a different boiling point; water boils
at 100 °C and ethanol at 78 °C. When a
mixture of water and ethanol is heated, the
ethanol will evaporate first because of its
lower boiling point and it will rise up the
distillation column. It then passes through the
condenser, which allows the ethanol to cool
and condense back to a liquid to be collected
in a flask (Figure 3).

17. TYPES OF DISTILLATION

18. PAPER CHROMATOGRAPHY
Paper chromatography is used to separate a mixture of solutes in a solvent. The mixture to be
separated is first dissolved in a solvent. This is known as the mobile phase. A piece of
chromatography paper is then placed in the solution. This is known as the stationary phase. Paper
chromatography is often used to separate the components of an ink. as shown in Figure 5. The yellow
component of the ink has a greater affinity for the mobile phase and has travelled further up the paper. The
purple complement of the ink has a greater affinity for the stationary phase and has travelled the least
distance up the paper.

19. RECRYSTALLISATION
A purification technique used to purify a
solute dissolved in a solution. It is used by
pharmaceutical companies to remove any
impurities that could contaminate
medication.The basic principles of the
recrystallisation process are as follows. The impure
mixture is first dissolved in a small volume of hot
solvent which should be just enough to completely
dissolve it. At this stage, any insoluble impurities
can be filtered off. The solution is then cooled
which causes the solubility of the dissolved solids to
decrease. The desired product forms crystals leaving
the soluble impurities in the solution which is then
filtered to obtain the pure product. In this way, the
purification of the solid is carried out (Figure 6).
Recrystallisation is also used to purify sugar crystals
from sugar cane juice. Figure 6

20. STATE OF MATTER AND CHANGES OF STATE
Solid, liquid and gas. A fourth state of matter – plasma – which is an ionised gas, exists mainly in
space.In this section we will focus on the three common states of matter which are solid, liquid and gas.
The three states differ in characteristics such as their shape or the ability to flow and in properties such as
density and compressibility.
https://javalab.org/en/status_solid_liquid_gas_en/
Kinetic molecular theory (KMT):
●All matter is made up of particles (atoms, molecules or ions).
●These particles all have kinetic energy (the energy of motion)
●The amount of kinetic energy is proportional to the temperature of the
substance
●Collisions between particles are elastic, which means no loss in kinetic energy.

21. Solids, Liquids, Gases

Let’s discuss and note down which are the macroscopic properties
of a solid, a liquid and a gas.

Does it flow?
Does it change shape to fill the container it is in?
Can it be compressed?


Solids, liquids and gases
Resources
??????
Matter Ability to flow Compressibility Hold their shape
Solids
Liquids
Gases
State symbols: Solid (s), Liquid in case of pure substance (l), gas (g), aqueous (aq) in case of
solution/mixture.

22. Scale Properties Description of particles
Solid Liquid Gas
Macroscopic

compressibility Not easily Not easily Easy
ability to flow none yes Yes
hold their shape yes Takes shape of
container
Takes shape of
container
Microscopic

particle separation touching touching separated
arrangement Regular pattern,
lattice
Not regular No arrangement
motion Vibrate about a
fixed position
Slide over each
other
Random
atterSolids, Liquids, Gases

24. Changes of state
State symbols: Solid (s),
Liquid in case of pure
substance (l), gas (g),
aqueous (aq) in case of
solution/mixture.

The state symbols (s), (l),
(g) and (aq) are also used
when writing equations
that represent chemical
reactions.
Changes of state (also called phase changes) occur when a substance
changes from one physical state to another.

25. Temperature and kinetic energy

The two temperature scales used in the DP
chemistry course are:
●The Celsius temperature scale is based on
the freezing point of water (0 °C) and the
boiling point of water (100 °C).
●The Kelvin scale is an absolute temperature
scale where the lowest possible value is 0 K,
known as absolute zero. At absolute zero, 0 K,
particles have zero kinetic energy. The
temperature in Kelvin is directly proportional
to the average kinetic energy of the particles in
the substance.So the particles in a substance at a
higher temperature have a higher average kinetic
energy than those at a lower temperature.



From Celsius scale to Kelvin scale +273
From Kelvin scale to Celsius scale -273
Unlike the Celsius scale, the Kelvin scale does not have
negative temperatures. One kelvin is equal to one degree on
the Celsius scale.

27. Heating and cooling curves
A heating curve shows how the state of matter changes as heat is added.





A heating curve shows how the state of matter changes as heat is added.

28. Changes of state and heat

29. Reflection
- The particle model of matter explains that all matter is composed of particles, which are in
constant motion and interact through forces.

- Changes in the state of matter occur as particles gain energy, increasing their kinetic energy
and causing transitions from solid to liquid to gas.

- Elements are the simplest form of matter, while compounds are chemically bonded
combinations of elements, and mixtures can be separated by physical means.

- The model helps in understanding electrical and magnetic properties by analyzing the
behavior of charged particles like electrons and ions.

- Solubility is influenced by factors like temperature and pressure, and the particle model aids
in understanding molecular interactions in solutions.

- The particle model and kinetic theory of gases together describe how gas particles move,
collide, and transfer energy, influencing properties like pressure, temperature, and volume.