Chapter 2: States Of Matter

Definition Matter
Matter can be defined as the material substance that constitutes the observable
universe. Matter, along with energy, is known to form the basis of all objective
phenomena. In the fields of classical physics and general chemistry, the term
matter is used to denote any material that has mass and takes up space by having
volume.
Matter can be classified into different states such as solid, liquid and gas on the
basis of intermolecular forces and the arrangement of particles.
Inter molecular attraction: Moleclues of all matters have a force of attraction, it is
known as inter molecular attraction. This force is the most in solid matters.

States Of Matter
The condition of the matter is one of the distinct forms that the various phases of
the matter take. Four states of matter can be found in daily life: solid, liquid, gas,
and plasma. Many other states, such as Bose – Einstein condensate and neutron
degenerate matter, are considered to occur only in extreme conditions such as
ultra-cold or ultra-dense matter. Other states, such as quark – gluon plasmas, are
thought to be possible but remain theoretical for the time being. Mainly there are 3
states of matter -

1). Solid: A Solid matter has a specific mass, volume and shape. Solids are
distinguished by a tight atomic bond and a high viscosity, resulting in a rigid form.
There are 2 kinds of solid -
I) Crystalline: Most solids are crystalline, in as much as they have a three-
dimensional periodic atomic structure.
II) Non Crystalline or Amorphous: Certain solids (such as glass) lack this
periodic arrangement and are non-crystalline or amorphous.
2). Liquid: Liquids have a specific mass and volume but do not have a shape. A
liquid is an almost incompressible fluid that conforms to the shape of its container
but retains a (nearly) constant volume independent of the pressure. Volume is
defined if temperature and pressure are constant. As the solid is heated past its
melting point, it becomes liquid as the pressure becomes greater than the triple
point of the material.
3) Gas: Gases have specific mass but they do not have specific volume or shape.
Within a gas, the molecules have enough kinetic energy such that the impact of the
intermolecular forces is small (or zero for the ideal gas) and the normal distance
between the adjacent molecules is much greater than the molecular size. The gas
has no definite shape or volume, but it occupies the entire container in which it is
confined.

Characteristics of the states of matter

1. Solids
# The solid state is one of the fundamental states of matter.
# Solids differ from liquids and gases by the characteristic of rigidity.
# The molecules of solids are tightly packed because of strong intermolecular
forces; they only oscillate about their mean positions.
# Whereas, liquids and gases possess the property of fluidity and can easily flow.
# Solids can be defined as the state of matter which has definite shape and volume
and has a rigid structure.
# Solids possess the least compressibility and thermal expansion.
# Example: Iron (Fe)

2. Liquids
# The molecules in a liquid are closely packed due to weak intermolecular forces.
# These forces are weaker than solids but stronger than that of gases.
# There is much space in between the molecules of liquids which makes their
flowing ability easy.
# Liquids can easily acquire the shape of a vessel, and they have a fixed volume.
# Conversion of solids into liquids takes place when we increase the temperature of
solids to a point where solids begin to melt.
# Generally, the density of liquid lies between the density of solids and gases.
Compressibility and thermal expansion of liquids are slightly higher than that of
solids.
# Example: Water (H2O)

3. Gases
# In this state of matter, distances between the molecules are large (intermolecular
distance is in the range of 10-7 – 10-5 cm).
# The intermolecular forces experienced between them are negligible.
# Thus, translatory, rotatory and vibratory motions are observed prominently in
gases.
# Gases do not have any fixed shape or volume.
# They also possess high compressibility and thermal expansion.
# Example: Oxygen (O2)

Kinetic theory of particles

O) It asserts that all stuff is made up of molecules or atoms that move around.
O) In Solid there are strong forces of attraction between the particles, which holds
them together at a fixed position to form a regular lattice structure. As the particles
are fixed, the overall substance keeps a definite shape and volume. But the
particles vibrate among them.
O) When more heat is applied on solid substance, particles gain more energy and
start to vibrate more and which weakens the force of attraction between them, and
at a certain temperature which is melting point the particles have enough energy to
break free of their bonds so the solid melts into liquid. In liquids there weak forces
of attraction between the particles so, they are free to move and are arranged pretty
randomly. However, the weak forces of attraction mean that the particles tend to
stick together and are fairly compact this means they have a definite volume even
though the overall shape can change allowing them to flow to fit a particular
container.
O) When more heat is applied on the liquid substance, the particles will again gain
more energy and this will make particles move around faster which weakens the
forces holding the particles together then when it reaches the boiling point the
particles will have enough energy to break the bonds altogether, and the liquid
boils or evaporates into gas, heat and the kinetic force in the particles is increased.
In gases, the force of attraction is very weak, the particles are far apart and can
travel around freely. So, gases don't have definite shape and volume. Instead they
always fill a container. As they spread out as much as possible. The gas particles
move in a straight line. When more heat is applied on this substance, the particles
will only increase the speed of movement. It may either expand in an expandable
container (Balloon) or increase it's pressure in a fixed shaped container (gas
cylinder).
O) If we cool gas down, the particles will have enough energy to overcome forces,
and the bonds will be created among the particles and gas is condensed into liquid.
Similarly, when liquid is cooled down, it results creating more attraction between
the particles and form solid substance fixing the particles in a place.
O) When we are working within a closed system -
# Changes in states won't change the mass as there are the same number of
particles.
# Only the density of substances will change.
Solid - Highest density
Liquid - Low density
Gas - Lowest density

Diffusion: The process in which solid, liquid and Gas moves from a place of
higher concentration to lower concentration is known as diffusion.
If a matter takes more time to spread it's rate of diffusion is higher and vice versa
Facts:
# The presence of heat increases the rate of diffusion of Solids.
# Rate of diffusion of liquid matter in another liquid is faster than in solid matter.
# In presence of heat gaseous matter diffuses fastest.
# The Gas with lesser atomic mass will have a better diffusion rate. Hydrogen is
the gas with the least atomic mass, it's diffusion rate is faster than other. While the
carbon dioxide being the one with most atomic mass, is the slowest.

Effusion: The passage of gases from a high pressure zone to a low pressure zone
through a fine pore is called effusion.
CNG - Compressed natural gas. (Basically, it is compressed methane gas at high
pressure.)
Difference of diffusion and effusion
Effusion and diffusion are by nature, the same kind of actions. The basic difference
between them is, effusion requires the presence of pressure but diffusion does not
depend on pressure. In diffusion, solid, liquid and gases matter spread in a suitable
medium but in effusion, only gas comes out through a fine hole from the container.
*) Organic compounds made of hydrogen and carbon are known as hydrocarbons.

Melting and Boiling

Melting: The process of transforming a solid matter into liquid by means of
applying heat is called melting.
Melting point: At normal pressure (1 atmospheric pressure), the temperature at
which a solid matter turns into liquid state is called the melting point of that solid.
Each pure solid matter has its own melting point, like the melting point of ice is
0°C.

Boiling: The process of transforming a liquid matter into gas by means of heat is
called boiling.
Boiling point: At normal pressure (1 atmospheric pressure), the temperature at
which a liquid matter turns into gaseous state is called the boiling point of that
liquid. Each pure liquid matter has its own boiling point, like the boiling point of
water is 100°C. The boiling process requires heat but solidification requires
removal of heat.
Facts:
# Finding melting point can be away to find the purity of solid substance.
# Boiling point can be a determiner of the purity of a liquid.
# The heat used in boiling and melting does not change the temperature of the
matter. It only transforms the state of the matter

Distillation and Sublimation

Evaporation: The process of heating a liquid and turning it into gas is called
evaporation or
vaporization.
Fact - Boiling and evaporation are both processes where a liquid turns into a gas,
but they differ in how they occur. Boiling happens at a specific temperature
throughout the liquid, while evaporation occurs at the surface and can happen at
any temperature. Boiling is a rapid process, while evaporation is slower.

Condensation: Again if we cool that vapor, the vapor turns into liquid. This
process is called condensation.
Condensation point: Condensation point is the temperature at which a gas
changes into its liquid state.
Distillation: The process of heating a liquid into vapor and then retrieving the
liquid from the vapor by cooling it is called distillation. That means,
Distillation = vaporization + condensation
Sublimation: The process in which heating a solid directly turns that solid into a
gaseous substance instead of a liquid, is called sublimation.
Sublimated substances: Matters that do not turn liquid if heat is applied. Instead,
they vaporize. These substances are called sublimated substances. Some of them
are -
Ammonium Chloride (NH¹Cl)
Camphor (C¹⁰H¹⁶O)
Naphthalene (C¹⁰H⁸)
Solid Carbon dioxide (CO²)
lodine (I²)
Aluminum Chloride (AICI³)
Deposition: The process through which a gas directly changes into solid without
going through liquid.
Freezing: The process of converting a liquid into a solid is called freezing.
Freezing point: The Freezing point is the temperature of a liquid at which it
changes its state from liquid to solid at atmospheric pressure.
Facts:
# If sublimated substance is mixed with some solid it can be retrieved by means of
the sublimation process.For example, if some ammonium chloride (NH,CI) is
mixed with some edible salt (NaCl), it can be separated by the process of
sublimation. If heat is continuously applied to a sublimated substance, it vaporizes.
In iodized salt, iodine is a sublimated substance. If you apply heat to that salt, the
iodine will be vaporized from there.
The vapor can be cooled into solid iodine. However, since the mixture of Sand and
glucose does not contain any sublimated substance, therefore, you cannot separate
them by sublimation