Question

What is the unit of ‘a’ in RK equation?

(a) Liter/mole

(b) Atm(liter/mole)

(c) Atm(liter/mole)K^0.5

(d) Atm(liter/mole)K

The question was posed to me in an internship interview.

This intriguing question comes from Equations of State in division Real Gases: Equations of State, Single Component Two Phase Systems, Saturation & Condensation of Basic Chemical Engineering

Answer 1

The correct option is (c) Atm(liter/mole)K^0.5

The explanation: RK equation is p = RT/(V – b) – a/[T^0.5V(V + b)], => unit of a = atm(liter/mole)K^0.5.