Van Der Waals Equation of State for Ideal Gas Assumption


The Redlich-Kwong equation of state is given as: P = (RT/v’-b) – a/(v’(v’+b)) Where a = 0.42748 (R2T2C/Pc) α, b = 0.08664 (RTc/Pc) and Tt = T/Tc, α = 1/Tr0.5 The value of gas constant R in these units is 0.08206 Liters - atm/g mol K Find the molar volume v’ of ammonia gas at 56 atm and 450 K using the Redlich–Kwong equation of state, Tc = 405.5 K, Pc = 111.3 atm. Solve this problem using any one of the four root-finding methods that you learnt in class or using the “goal seek” functionality in Excel. Employ your own stopping criteria. How good is the ideal gas assumption here?

Solve the above problem by employing the Van Der Waals Equation of State.

Without using Excel, employ any of the four methods that you learnt in class (Bisection,

False Position, Secant, Newton Raphson) to solve this problem. Decide your own stopping criteria.

P = RT/(v’- b) – (a/v’)



The question belongs to Chemical Engineering and it is about Van Der Waals equation with a gas constant and finding molar volume of ammonia gas. The calculations have been given in the solution.

Total Word Count 76


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