Question

The value of R in L-atm $$\text{mo}{\text{l}}^{\text{-1}}{K}^{-1}$$is:
(A) 0.0821
(B) 82.1
(C) 8.314
(D) 831.4

Answer 1

Hint: R is referred to as the universal gas constant in chemistry. It is the gas constant which is the proportionality constant which helps to relate the energy scale to the temperature scale at the given temperature which is for the moles of the particles. The unit for gas constant has a varying nature which depends on the other units which are used in the equation.

Complete answer:The R is the ideal gas constant which is the universal gas constant which helps to qualify the relationship between the gaseous properties. The symbol L is used in the equation for defining volume in litres, atm is used to define pressure as atmosphere and mol is used for the number of moles and K is used to define temperature in kelvin. The formula for ideal gas law using the STP conditions is the following:
$$R={\displaystyle \frac{PV}{nT}}$$
So at STP
P= 1 atm
V= 22.4L
n= 1 mol
T= 273 k
On substituting the values in above formula we get,
$$R={\displaystyle \frac{1\times 22.4}{1\times 273}}=0.0821$$
So the value of R is 0.0821.

So the correct option for this answer is option (A).

Note:The gas law is a combination of the constants of the four laws. These are Charles law, Boyles law, Gay Lussac law an Avogadro law. The Charles law states that the volume of the ideal gas is directly proportional to the Absolute temperature when the pressure remains constant. Boyle's law states that when the temperature is constant the exerted pressure by gas is inversely proportional to the volume occupied by it.