Question

In the ideal gas equation, the unit of universal gas constant R is?
(A) ${\text{Mole - atm/K}}$
(B) ${\text{Litre/mole}}$
(C) ${\text{Litre - atm/mole}} \cdot {\text{K}}$
(D) ${\text{erg/K}}$

Answer 1

Hint: The Ideal gas law is also known as a general gas equation, which is the equation of state of a hypothetical ideal gas. It is a good approximation of the behaviour of many gases under many conditions although it has several limitations.

Complete step by step answer:
> The ideal gas law states that the product of the pressure and volume of a one-gram molecule of an ideal gas is equal to the product of the absolute temperature of the gas and universal gas constant.
> In ideal gas equation which is written as:
${\text{R = }}\dfrac{{{\text{PV}}}}{{{\text{nT}}}}$
P is the pressure in atmosphere or atm
V is the volume in Litre
n is the number of moles
T is the temperature in kelvin or K.
So unit of R = ${\text{Litre - atm/mole}} \cdot {\text{K}}$
Therefore, the correct option to this question is Option C.

Additional Information: In the equation R is a universal constant which is the product of the Boltzmann constant with the Avogadro constant. Its value is ${\text{R\; = 8}}{\text{.314 joule per kg}}$ and per mole ${\text{ = 0}}{\text{.08206 Litre - atm/mole}} \cdot {\text{K}}$

Note: An ideal gas is a gas that obeys Boyle's law, Charle’s law and avogadro's law at variable pressure and volume and temperature called the ideal gas law.
The ideal gas law tends to fail at lower temperatures and higher pressures. The ideal gas law also fails for most of the heavy gases, such as refrigerants.