2.1.
2 – Practical Model
2.1 Kinetic Particle Model of Matter
2.1.2 Practical Model
States of Matter
States of Matter: There are three states of matter.
1. Solid
2. Liquid
3. Gas
Kinetic Molecular Model of Matter
State of Matter Arrangement of particles Movement of Particles
1. Closely packed. 1. Particles vibrate
about their mean
2. Occupy minimum space. positions.
3. Regular pattern. 2. Very strong
intermolecular
forces between them.
1. Occurs in clusters (groups). 1. Free to move about
between clusters but
2. Molecules are slightly further confined within the
apart. vessel.
3. When flow, slide over 2. Weak intermolecular
each other. forces between them.
1. Very far apart. 1. High speed,
independent motion
2. Occupy any available space. in random manner.
2. Weakest
intermolecular
forces between them.
Page 1 of 6 By Rizwan Khalil (0 33 55 66 77 70)
2.1.2 – Practical Model
Relationship Between Motion of Particles and Temperature
With an increase in temperature, the particles move faster (velocity increases)
as they gain kinetic energy, resulting in increased collisions between them.
With an increase in temperature, the particles gain kinetic energy and vibrate
faster and more strongly.
Note:
1. When temperature increases, velocity increases, number of collisions between
particles increases and their kinetic energy also increase.
2. When temperature decreases, velocity decreases, number of collisions
between particles decreases and their kinetic energy also decreases.
Result:
The motion of particles (kinetic energy) is directly proportional to increase in
temperature.
Absolute Zero or Zero of Kelvin: There is a lowest possible temperature
(-273 °C or 0 K), known as absolute zero or zero of kelvin, where the particles
have least kinetic energy.
Page 2 of 6 By Rizwan Khalil (0 33 55 66 77 70)
2.1.2 – Practical Model
Pressure and Gas Pressure
Pressure: Force exerting per unit area perpendicularly.
𝑭
Formula: 𝑷= 𝑨
Unit: Pa or N m-2
How Gas Exerts Pressure:
The pressure exerted by a gas is due to the random motion of particles in
the gas. Gases have weak intermolecular forces and the particles are in continuous
random motion. These particles collide with the walls of the container exerting
force per unit area results in exerting pressure.
Temperature and Pressure of Gas:
The temperature of the gas is proportional to the average kinetic energy of its
molecules. As temperature of gas increases, faster moving particles will collide
with the walls of the container more frequently and with greater force.
This causes the force per unit area on the walls of the container to increase and
so the pressure increases.
Page 3 of 6 By Rizwan Khalil (0 33 55 66 77 70)
2.1.2 – Practical Model
Relations Between Pressure, Volume and Temperature
(PVT)
At Constant “Pressure (P)”:
The Volume of a fixed amount of gas is directly proportional to Temperature if
Pressure is kept constant.
V T
𝑉
𝑇
= 𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡
𝑉1 𝑉2
=
𝑇1 𝑇2
Note: Pressure is kept constant during experiment.
Page 4 of 6 By Rizwan Khalil (0 33 55 66 77 70)
2.1.2 – Practical Model
Relations Between Pressure, Volume and Temperature
(PVT)
At Constant “Volume (V)”:
The Pressure of a gas is directly proportional to Temperature if Volume and
amount of gas is kept constant.
P T
𝑃
= 𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡
𝑇
𝑃1 𝑃2
=
𝑇1 𝑇2
Note: Volume is kept constant during experiment.
Page 5 of 6 By Rizwan Khalil (0 33 55 66 77 70)
2.1.2 – Practical Model
Relations Between Pressure, Volume and Temperature
(PVT)
At Constant “Temperature (T)”:
For a given mass of a gas, Pressure of a gas is inversely proportional to Volume if
Temperature of gas is kept constant.
𝟏
P
𝑽
𝑃 𝑉 = 𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡
𝑃1 𝑉1 = 𝑃2 𝑉2
Note: Temperature is kept constant during experiment.
Page 6 of 6 By Rizwan Khalil (0 33 55 66 77 70)
