Question

Calculate molar volume of a gas at STP.

Answer 1

Hint: Ideal Gas Equation is the equation defining the states of the hypothetical gases expressed mathematically by the combinations of empirical and physical constants. It is a relation between pressure, volume, number of moles, and temperature.

Complete step by step answer:
At standard Temperature and Pressure (STP) the molar volume \[\left( {{{\rm{V}}_{\rm{m}}}} \right)\] is the volume occupied by one mole of a chemical element or a chemical compound.
We know that at STP, \[{\rm{P = 1 atm}}\], \[{\rm{T = 273 K}}\], \[{\rm{n = 1 moles}}\] and\[{\rm{R = 0}}{\rm{.0821 L - atmmo}}{{\rm{l}}^{ - 1}}{\rm{ }}{{\rm{K}}^{ - 1}}\].
Ideal gas equation is given as –
\[{\rm{PV = nRT}}\]
\[{\rm{V = }}\dfrac{{{\rm{nRT}}}}{{\rm{P}}}\]
\[{\rm{ = }}\dfrac{{0.0821{\rm{ }} \times {\rm{ 273}}}}{1}\]
\[{\rm{V = 22}}{\rm{.4 L}}\]
Therefore, we have V = 22.4 L
Hence, the molar volume of a gas at STP is 22.4 litres.

Additional information:
Ideal gas equation was made by combining various gas laws such as Charles’s law, Boyle’s law, Gay-Lussac’s law and Avogadro’s law.The ideal gas law is the equation of state of a hypothetical ideal gas. It is an approximation of behaviour of gases under given conditions.
An ideal gas is a hypothetical gas consisting of randomly moving particles that undergo fully elastic collisions. Even though there is no such thing as an ideal gas, most of the gases tend to reach these properties when their density decreases. This happens because the intermolecular distances between gas molecules are so large that they do not interact with each other as such.
At extremely low densities, all real gases show ideal behaviour and tend to obey one universal law which we call as ideal gas law or ideal gas equation.

Note: Hence, in all the standard conditions of temperature, pressure and number of moles, the molar volume is 22.4 Litre which is also considered as a standard.