Problem 2: Normal-butane is stored in canisters for camp cooking stoves. The ambient temperature is 85 °F and assume that the canisters have the same temperature. a) Use Lee-Kesler's correlation to calculate the n-butane vapor pressure inside the canister. (5 points) b) Compare the vapor of propane at the same temperature as in Problem 1. Which gas, propane or butane, requires a stronger tank? (5 points) c) Use the formulation of van der Waals EOS to calculate the Z factors for the vapor and liquid inside the canisters. (20 points) i. Calculate a, b, A, B as shown in class ii. Formulate the cubic equations with respect to Z iii. Solve the cubic equation with any software such as MATLAB, or you may solve it graphically as demonstrated in class iv. Rank the three roots from the smallest to the largest d) Calculate the liquid and vapor densities inside the canisters (5 points) Use these parameters for your calculation. Acentric factor w=0.193, critical temperature Tc = 305.62°F, critical pressure pc = 550.6 psia.

Fig: 1