The Gaseous State

Introduction 

As we know, there are three states of matter or matter states: solid states, liquid states and gaseous states. All matter states have different properties. The gaseous state is the simplest state. We live in the lowermost part of the atmosphere which is the troposphere and at this layer different types of gases are present. 

It is also easy to find the average speed of gas molecules. The specification of gaseous state is that they  help in propagation of waves.They provide a medium in which waves can transmit from one point to another point. Another specification of gaseous state is because absences of boundary gases tend to occupy whole volume present in space and in other matter definition they have defined boundaries. So, their volume is also defined.

Molecules present in the gas state have relatively less density and viscosity then molecules present in other matter states.

We are going to briefly talk about the properties of gases and their measurement factors.

Properties of gaseous state

• Specification of gaseous state is that they don’t have definite shape and volume.
• Expansibility: Gases have boundless expansibility. They extend to fill the whole vessel they are set in.

• Compressibility: We can utilise pressure to compress the gases. For this we don’t need a lot of effort. We can fill the same volume of gas in two different containers of different shapes and sizes by applying pressure.
•  Diffusibility: Gases can diffuse quickly through one container to another container. Gases have the property which is independent from the force of  gravitation and the property is known as Diffusion. Due to the presence of this property, gases can easily mix with each other and remain almost uniformly distributed in the atmosphere.
• R=(Volume Diffused/TimeTaken)=V/T

Measurable Properties Gaseous State

Measurement of mass gases

Weighing helps in measuring the mass or amount of gas in gaseous state. We firstly measure the container in which the gas is present. Again according to the definition of matter, we have to measure the mass or amount of the container after removing all the gas present in it.The specification of gaseous state is that mass of gas is the difference of weight of two gases.

That is,

Mass of gas=(weight of container containing the gas)-(weight of container after removing all the gases present in it)

Unit of mass: In SI units, mass is generally expressed in kilograms. 

The mass of gas is commonly expressed in terms of numbers of moles (n). The mass is related to the numbers of moles as

No. of moles (n) =mass of substance (gas)/Molar mass .

The value of 1 mole is equal to 6.022*1023. 

Measurement of Volume of gases

The space occupied by the substances is known as its volume. . The gas is a state of matter that occupies the entire space inside the container available to it, that is why the volume of  gas is the same as the volume of the container. Therefore  the matter definition states that we only require to measure the volume of the container in which the gas is present. 

Unit of Volume: We express volume in units of litres (L). The SI unit of volume is cubic metre  (m3).

Measurement of Pressure of gases 

When we apply force on a unit area then it is known as Pressure. Barometer is a device or instrument  which is very helpful in measurement of atmospheric pressure. Gases exerts uniform pressure in all the directions on the walls of the containers in which they are confined. Thus,the pressure of the gas is the force exerted by the gas per unit area of the walls of the container.

Pressure = Force/Area =F/A

Atmospheric Pressure 

The pressure exerted by the gases present in the atmosphere on the surface of the earth is called atmospheric pressure.

Unit of atmospheric pressure

The maximum height of the mercury which can be supported by the atmospheric pressure provides a measure of  pressure.

1 atm = 76.0 cm of mercury (cm Hg) 

1 bar =0.987atm.

Measurement of Temperature of gases 

We measure temperature by the hotness or coldness of a body. When the temperature of a body is high then it is known as Hot body and when temperature is low then it is known as Cold body. Thermometer is a device which is helpful in measuring temperature. 

Mercury is the substance that is mainly used in thermometers for measuring temperature.

Unit of Temperature: 

SI unit of Temperature is degree Kelvin (K) and the scale is known as Kelvin scale. The zero point on the Kelvin scale is known as Absolute temperature. 

K = 0C + 273.15

F = (9/5) 0C + 32

Conclusion 

Gas molecules have extremely high velocity due to which collisions occur and due to these collisions velocity of gas molecules changes in a very short period. Thus, we conclude that  all the states of matter in  gaseous or vaporous states have different physical and chemical properties.

When  gases do not have any kinetic energy at that time they behave like an Ideal gas as conditions start changing they start gaining kinetic energy and start deviating from their ideal gas behaviour.

At last we conclude that gases are very useful as well as harmful for humans, animals and also for nature.