Question

How do you use the ideal gas law ?

Answer 1

Ideal gas is a theoretical gas composed of randomly moving particles in which there is no interaction between the molecule itself. Ideal gas law stated as:

$\mathrm{PV}=\mathrm{nRT}$

where, $\mathrm{P}$ is the pressure

$\mathrm{V}$ is the volume

$\mathrm{T}$ is the temperature

$\mathrm{R}$ is the ideal gas constant

$\mathrm{n}$ is the number of moles

Ideal gas law states that if any three above physical variables are known, we can find the fourth one.

Example: What is the pressure of the $0.556\mathrm{mol}$ gas having volume $16.05\mathrm{L}$ and temperature of $58°\mathrm{C}$ ?

Solution:

Step 1: Temperature $=58°\mathrm{C}+273$

$=331\mathrm{K}$

Volume $=16.05\mathrm{L}$

No. of moles $=0.556\mathrm{mol}$

Step 2: Substitute given variables in the Ideal gas equation formula

$\mathrm{P}=\mathrm{nRT}/\mathrm{V}$

$\mathrm{P}=(0.556\mathrm{mol}\times 0.0821\mathrm{Latm}{\mathrm{mol}}^{-1}{\mathrm{K}}^{-1}\times 331\mathrm{K})/16.05\hspace{0.17em}\mathrm{L}$

$\mathrm{P}=0.941\mathrm{atm}$

Therefore, the above paragraph and numerical clearly state the use of the Ideal gas law.