Gas Laws and the Concept of Molecule

Gas molecules are made of a number of atoms bonded to each other. The interatomic bonds are identical to springs combining atoms of different masses together. The bonding will vibrate with the constant frequency known as natural frequency. When the infrared radiation interacts with the gas molecule, some amount of energy is absorbed. However, the remaining radiation gets transmitted. When the gas molecule absorbs such radiation, the molecules gain energy and vibrate.

 The gases have widely spaced the individual particles. There are various scientists that do numerous experiments regarding the concept of gases and therefore put forth the gas laws associated with the various variables of a gas. The gas state variable seems to be volume, temperature, pressure, and amount of substance.

The gas laws can be defined as the group of laws that governs the gas’s behaviour through offering the relationship. The five gas laws are: 

• Boyle’s Law

• Charles Law

• Gay-Lussac’s Law 

• Avogadro’s Law 

• Combined Gas Law 

Boyle’s Law 

Boyle’s law determines the relationship between the volume and pressure of the gas.

Charles’s Law 

It determines the relationship between the gas’s absolute temperature and volume occupied.

Gay –Lussac’s Law 

Gay Lussac’s law is a law that provides the relationship between the pressure exerted by the gas on the container walls and absolute temperature related to the gas.

Avogadro’s Law 

It helps determine the relationship between the amount of the gaseous substance and the volume occupied by the gas.

Combined Gas Law

The combined gas law is also known as the ideal gas law, which can be obtained by combining the above four laws discussed, i.e., Charles law, Boyle’s law, Gay –Lussac’s law, and Avogadro’s law.

Concerning the standard condition, all the gases show identical behaviour. The variation in the behaviour will take place when the physical parameter related to the gas has been changed, i.e., volume, pressure, and temperature of the gas.

Importance of Gas Law 

Gas law plays an important role because the above-discussed laws can be employed for describing the significant parameters of the gas mass through employing theoretical means. When the pressure and volume of the mass of gas are identified, we will be able to measure its temperature by using the Ideal gas equation. 

Use of Gas Law

Gas laws are used for comparing two different gases and also help in identifying the properties of the gas.

Importance of Ideal Gas Law 

Ideal gas law refers to the simple equation of the state followed by most gases, particularly at high temperatures and low pressures. The simple equation of the ideal gas law is associated with volume, temperature, and pressure for the fixed moles of almost every gas. In numerical notation, ideal gas law is defined as 

PV = nRT

R refers to a constant known as the universal gas constant equal to the value of 0.0821 L-atm / mole-K

• n determine the number of moles

• P refers to the pressure 

• T determine the temperature of the gas

Let us suppose, if the temperature associated with the refrigerated balloon gets lower, the volume of the gases with the balloon also gets lower down too. By combing each thing into one proportion, we will get 

The volume of gas is directly proportional to the Kelvin temperature of the gas; however, inverse relationship to the pressure or proportional to the ratio of Kelvin temperature and its pressure.

Therefore, a constant will took place i.e.

PV/T=C 

It indicates that when the pressure of a gas increases, the temperature will also increase and go vice versa.

Therefore, both initial and final volumes and temperatures under constant pressure can be measured.

P1V1 / T1 = P2V2 / T2 = P3V3 / T3 etc.

The gases’ behaviour will be identical throughout an extensive combination of the conditions due to the reason that molecules are widely spaced, and also, the equation of the state for the ideal gas is determined using the kinetic theory. Kinetic theory of gases refers to the theoretical model that defines the molecular composition of gas in terms of the large number of submicroscopic particles which comprise molecules and atoms.

Rules for the use of Ideal Gas Law

• Convert temperature (T) to Kelvin’s (K), always.

• Always convert volume (V) to litres (L) always.

• Convert mass (m) to moles (mol), always.

• It is much more effective to convert the value of pressure into Kilopascals (kPa). Universal Gas Constant, R will be 8.314 (L.kPa)/ (mol · K).

Gas Law Problems

Let us consider a sealed jar whose volume is 1L and comprises 1 mole of air at a temperature of 20-degree Celcius, supposing that air shows the behaviour of ideal gas. Calculate the value of pressure available inside the jar in Pa?

Answer 

According to the equation of the ideal gas law equation, i.e., PV=nRT

The value of variables are 

Solution:

By solving with the help of ideal gas equation

PV=nRT

(1) By rearranging the equation we can get,

n= 1

R= 8.314J/K/mol

T= 20degree Celsius =293.15K

V=1L=0.001m3

Now, we will put the value of the variable in the ideal gas equation

P= nRT/V

P=(1*8.314*293.15)/0.001

P= 2,437,249

P=2.437*10^6 Pa

Therefore, the pressure inside the jar is approximately 24atm.

Application of Gas Laws

It is seen that during the season of summer, when both pressure and temperature seem to be high, a tire will be at risk of bursting due to the reason that it is being inflated with air. Another example can be seen that when we start climbing the hill, we feel some issue related to inhaling. What’s the reason behind it?

When the physical condition is altered with a change in environment, the gases particles’ behaviours also derive from their normal behaviour, and such alteration in the gas behaviour can be examined by reviewing the different gas laws. The concept of gas law is also used in studying fluid dynamics and thermodynamics along with weather forecast systems. In general words, we can say that Gas laws are used for comparing two different gases and also help in identifying the properties of the gas.

Conclusion 

We have discussed the role of gas law in elucidating the concept of the molecule. There are five types of gas laws defined above, which have been named after the scientist who discovered them. The main use of gas laws is to compare the different gases and also helps in recognizing the properties of the gas. 

That was all about the explanation for the role of gas laws related to the concept of molecules. If you still have any doubts or suggestions, let us know by putting a comment in the box given below.