What is the Difference Between Universal Gas Constant and Characteristic Gas Constant?

The main difference between the Universal Gas Constant and the Characteristic Gas Constant lies in their applicability and the factors they depend on. Here are the key differences:

• Universal Gas Constant: This constant is applicable only for an ideal gas. It is calculated using standard temperature and pressure (STP) values. An ideal gas is a hypothetical gas that has properties that are very different from real gases. The Universal Gas Constant is used in the ideal gas law, which is formed to explain the behavior of an ideal gas.
• Characteristic Gas Constant: This constant is applied for a real gas. It is calculated with STP values along with the molar mass of the real gas. A real gas is a gas that has properties that are different from an ideal gas, and none of the real gases behave as an ideal gas. The Characteristic Gas Constant is used with a modification to account for the differences between real gases and ideal gases.

In summary, the Universal Gas Constant is applicable for ideal gases and is calculated using STP values, while the Characteristic Gas Constant is applicable for real gases and is calculated using STP values along with the molar mass of the real gas.

Comparative Table: Universal Gas Constant vs Characteristic Gas Constant

The universal gas constant and the characteristic gas constant are both used in the ideal gas law, but they differ in their applicability and dependence on the gas. Here is a table summarizing the differences between the two:

The universal gas constant is used for ideal gases and is calculated using standard temperature and pressure values. It is independent of the gas taken and has a fixed value of 0.082057 L/(K.mol). On the other hand, the characteristic gas constant is applicable for real gases and is calculated with STP values along with the molar mass of the real gas. It is dependent on the gas and its value will always depend on the gas.