Question

What is main difference between characteristic gas constant and universal gas constant

Answer 1

Universal gas constant is only applied for an ideal gas. Characteristic gas constant is applied for a real gas.
Universal gas constant is calculated using standard temperature and pressure (STP) values. Characteristic gas constant is calculated with STP values along with the molar mass of the real gas.
Universal gas constant is independent of the gas taken. Characteristic gas constant is dependent on the gas.
The value of universal gas constant is 0.082057 L/(K.mol). The value for characteristic gas constant will always depend on the gas.