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Problem 1: Normal-butane is stored in a steel tank and the temperature of the tank and butane inside is kept at a constant temperature T = 85°F Use these parameters for your calculation. Acentric factor w = 0.193, critical temperature Tc = 305.62°F, critical pressure pc = 550.6 psia, Vc = 4.1 ft³/lbmol. a) Use Lee-Kesler's correlation to calculate the n-butane vapor pressure inside the canister. (5 points) b) Write down the van der Waals EOS and calculate the constants a, b using the critical properties given above. Use n = 1 pound-mole, or Ibmol. (5 points) c) Calculate the critical volumes Vc, ft³/lbmol, from VDW EOS. Compared the calculated Vc and the given value. (5 points) d) Plot pressure p vs. volume V for one Ibmol of butane gas. Use Vmin = b + 0.2, V₁ = 1.02Vmin, V₂ = 1.02V₁, V3 = 1.02V₂, ... until Vmax > 150 ft³. (10 points) a) Using VDW EOS b) Using the Ideal Gas EOS e) Use the calculated vapor pressure, and p vs. V plot to estimate the system volumes at the dew point and bubble point, respectively. (5 points)

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