Introduction: The Properties of gases and liquidsThe distance between molecules decides whether that substance exists in solid, liquid or gaseous state.
As the intermolecular distances go on increasing, the phase changes from solid to liquid to gas.
The properties of liquids and gases are discussed as under.
Properties of Liquids
Liquids have definite volume but not definite shape. They assume the shape of the container. Liquids cannot be compressed.
Their volume can vary with temperature. As the temperature increases, so does the volume.
Liquids when mixed would tend to diffuse into one another.
Liquids when heated may turn to gas or to solid when cooled. These points of temperature are called as boiling points or melting points respectively.
They exhibit viscosity which is the measure of ease with which molecules pass over one another. More the viscosity less would be the ease of flow.
They also exhibit the phenomena of surface tension because the molecules on surface layer are attracted only from below side.
Properties of Gases
Gases have neither definite volume nor definite shape. They fill the container.
Gases can be compressed. Their volume can vary with temperature. As the temperature increases, so does the volume.
Gases when mixed, would tend to diffuse into one another.
Gases when heated may turn to plasma or to liquid [normally] when cooled. This point is called boiling point.
Physical properties of gases are affected by change in pressure, volume and temperature.
Important properties of gases and the laws
Boyle developed his law that the volume of a gas varies with the pressure inversely at fixed temperature.
PV = Constant
Similarly Charles developed the relationship between the volume and temperature at fixed pressure. It says that as the temperature increases, so does the volume of a gas.
V = T x Constant
The above two relations were expressed combinedly known as 'Universal gas law'
P1V1/T1 = P2V2/T2
Ideal gas law
This relationship was discovered from the above laws and is represented by,
PV = nRT
where n means number of moles, R is gas constant and T is temperature in Kelvin.
In a mixture of gases, pressure exerted by each gas is known as partial pressure. Dalton discovered that the total pressure is equal to sum of partial pressures.
As the intermolecular distances go on increasing, the phase changes from solid to liquid to gas.
The properties of liquids and gases are discussed as under.
Properties of Liquids
Liquids have definite volume but not definite shape. They assume the shape of the container. Liquids cannot be compressed.
Their volume can vary with temperature. As the temperature increases, so does the volume.
Liquids when mixed would tend to diffuse into one another.
Liquids when heated may turn to gas or to solid when cooled. These points of temperature are called as boiling points or melting points respectively.
They exhibit viscosity which is the measure of ease with which molecules pass over one another. More the viscosity less would be the ease of flow.
They also exhibit the phenomena of surface tension because the molecules on surface layer are attracted only from below side.
Properties of Gases
Gases have neither definite volume nor definite shape. They fill the container.
Gases can be compressed. Their volume can vary with temperature. As the temperature increases, so does the volume.
Gases when mixed, would tend to diffuse into one another.
Gases when heated may turn to plasma or to liquid [normally] when cooled. This point is called boiling point.
Physical properties of gases are affected by change in pressure, volume and temperature.
Important properties of gases and the laws
Boyle developed his law that the volume of a gas varies with the pressure inversely at fixed temperature.
PV = Constant
Similarly Charles developed the relationship between the volume and temperature at fixed pressure. It says that as the temperature increases, so does the volume of a gas.
V = T x Constant
The above two relations were expressed combinedly known as 'Universal gas law'
P1V1/T1 = P2V2/T2
Ideal gas law
This relationship was discovered from the above laws and is represented by,
PV = nRT
where n means number of moles, R is gas constant and T is temperature in Kelvin.
In a mixture of gases, pressure exerted by each gas is known as partial pressure. Dalton discovered that the total pressure is equal to sum of partial pressures.