Ideal Gas Law Calculator [pv=nrt]

The ideal gas law calculator helps you determine the properties of an ideal gas as subjected to volume, temperature or pressure changes. Let’s cover details on how to use the calculator, the ideal gas equation, and more about ideal gas. When it comes to the ideal gas law, there are a lot of things to learn. This law also involves several equations which you may have to know about even while using the ideal gas law calculator.

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How to use the ideal gas law calculator?

This ideal gas law calculator is also known as a gas pressure calculator, a molar volume calculator or a gas volume calculator because you can use it to find different values. It’s very simple, easy to use, and easy to understand. Here are the steps to follow when using this online tool:

  • You can use this calculator in different ways. Upon loading, the calculator is ready for use.
  • When you input any value, the other values change automatically.
  • All you have to do is enter the value for the Pressure, Volume, Amount of Substance or Temperature.
  • Then choose the unit of measurement as needed.

What is the formula for the ideal gas law?

An ideal gas refers to a special case of any kind of gas which fulfills these conditions:

  • It consists of a huge amount of molecules which randomly move around.
  • All of the molecules are point particles which means that they don’t take up space.
  • All of the molecules don’t interact with each other except when they collide.
  • All of the collisions which occur are completely and perfectly elastic.
  • All of the particles obey the laws of motion.

To find the value for ideal gas without using the ideal gas law calculator, use the ideal gas equation:

pV = nRT

p refers to the gas pressure which you measure in Pa
V refers to the gas volume which you measure in m3
n refers to the substance amount which you measure in moles
R refers to the ideal gas constant
T refers to the gas temperature which you measure in Kelvins

What does the ideal gas law state?

The ideal gas law which is also known as the general gas equation refers to the equation of state of an ideal gas that’s hypothetical. It’s an acceptable estimation of the behavior of most gases under different conditions but it has a number of limitations. Often, we write the ideal gas law as:

pV = nRT

where p refers to pressure, V refers to volume, and T refers to the absolute temperature. n refers to the number of moles of gas while R is an ideal gas constant which means that the value is the same for all types of gases.

You can also derive this equation from the microscopic kinetic theory as independently achieved by August Krönig in the year 1856 and by Rudolf Clausius in the year 1857. For any amount of gas, you can determine its state by its volume, temperature, and pressure. This equation has a modern form which related these in two main simple forms:

Common form

For this form, the most frequently introduced equation is:

PV = nRT = NkBT

P refers to the gas pressure
V refers to the gas volume
n refers to the gas substance amount
N refers to the number of gas molecules
R refers to the universal or ideal gas constant that’s equal to the product of the Avogadro constant and the Boltzmann constant
kB refers to the Boltzmann constant
T refers to the gas absolute temperature

When you use SI units, use pascals as the unit of measurement of P, cubic meters as the unit of measurement of V, moles as the unit of measurement of n, and kelvins as the unit of measurement of T. For R, the value is 8.314 J/(K•mol) ≈ 0.08206 L•atm/(mol•K) or 2 cal/(K•mol)

Molar form

You can specify the amount of gas present by using the mass rather than the gas’ chemical amount. In such a case, you may use an alternative form of the ideal gas law. The chemical amount n which you measure in moles equals the gas’ total mass m which you measure in grams divided by the molar mass M which you measure in grams per mole.

n = m / M

When you replace n with m/M and introduce density ρ = m/V, you get

PV = (m/M) RT

P = m RT
         V M

P = ρ R T

When you define the specific gas constant as the ratio R/M:

P = ρRspecificT

The molar form of the ideal gas law is extremely useful since it connects density, temperature, and pressure in a distinct formula that’s independent of the quantity of the gas you’re considering. Alternatively, you may also write this law in terms of the specific volume v, the reciprocal density as:

Pv = RspecificT

It’s very common, especially when it comes to engineering applications, to use the R symbol to represent the value of the specific gas constant. In these cases, you can use a different symbol for the universal gas constant namely R with a line on top to differentiate it.

No matter what the case is, the units or the context of the gas constant must clarify whether you’re referring to the specific or universal gas constant.

What is the gas constant in the ideal gas law?

The gas constant which has R as its symbol is also known as the universal or molar constant. You can use this in a lot of fundamental formulas and equations like the ideal gas law. This gas constant has a value of 8.3144598 J/(mol * K).

Often, you can define this gas constant as the product of the Avogadro number which is the number of atoms in one mole of substance and the Boltzmann’s constant which relates the temperature of a certain gas and the kinetic energy. Therefore:

R = k/N = 1.38064852)*10^(-23) J/K /(6.022140857 * 10^23 1/mol) = 8.3144598 J/(mol * K)