Question

How do you use $pV = nRT$ in chemistry?

Answer 1

This equation is actually very familiar for us as it is the ideal gas law which determines properties of an ideal gas. Here we have to know the actual use of this equation as it can be used when we are provided with three of four properties of a gas like volume, pressure, temperature and number of moles. Also this ideal gas law is a good approximation of behavior of so many gases which is under many conditions.

Formula used: $pV = nRT$
Here , $p =$ pressure of gas
$V =$ volume of gas
$n =$ amount of gas
$R =$ ideal gas constant $= 8.314\dfrac{{L.kPa}}{{mol.K}}$
$T =$ temperature of gas

Complete step-by-step answer:
First of all we have to know that the given equation is the ideal gas law which is determining the properties exhibited by an ideal gas.Next thing we have to remember is that an ideal gas is a simplified model of real gas which will be allowing us to use with simple calculations and formula. Before going to the details of usage of the given particular equation we have to know in a brief about this ideal gas equation.

Once again let us write the formula here with explaining each part of the equation. So, the given equation is $pV = nRT$. Here $P$ is describing the pressure of gas but we have to remember that it is always measured in $kPa$.

$V$ is an important part as it is the volume of the particular gas and they are usually measured in litre. $n$ is the amount of gas so that it is measured in $moles$ which describes the amount.
$R$ in here is the ideal gas constant which is in a constant magnitude of $8.314\dfrac{{L.kPa}}{{mol.K}}$
$T$ describes the temperature of gas usually denoted in Kelvin.

Here $R$ is a universal constant . We know that there are actually four unknowns in this particular gas equation. So , if there is any one unknown quantity among them we need the other three quantities in order to find the unknown one. Let us go through an example to understand this. If we need to find volume , we should require values of temperature, amount of gas and pressure.

Next we have to look into the main usage of the above equation. Usually ideal gas equations are often used during combination with other gas laws which are actually used to calculate gas properties as these gases are subjected to undergo certain changes. These particular gas law includes Boyle’s law , Charles’s law , Gay-Lussac’s law, Avogadro’s Law , Dalton’s Law , the law of combining volumes and Combined gas law.

In this way , we use $pV = nRT$ in chemistry.

Note: Actually the main thing regarding this question is we have to be familiar with this important equation because then only we can identify which law does it belong to. We have to know that one unknown quantity from the equation can only be found when the other three are given. In general, we can understand that the ideal gas law states that the pressure, temperature and also volume of a gas is related to each other. Also we need to note the point here that this law does not make any comments or statements regarding heating or cooling of gas during compression or expansion.