Draw and label the given streams and derive expressions for the indicated quantities in

QUESTION:

Draw and label the given streams and derive expressions for the indicated quantities in terms of labeled variables. The solution of Part (a) is given as an illustration. (a) A continuous stream contains 40.0 mole% benzene and the balance toluene. Write expressions for the molar and mass flow rates of benzene, n_ Bmol C6H6/s and m_ Bkg C6H6/s, in terms of the total molar flow rate of the stream, n_mol/s. ENVIRONMENTAL 174 CHAPTER 4 Fundamentals of Material Balances WEBC04 06/04/2015 20:34:56 Page 175 Solution n_mol/s ! 0:400 mol C6H6/mol 0:600 mol C7H8/mol n_B 0:400n_ mol C6H6/s m_ B 0:400n_ mol C6H6 78:1gC6H6 mol 31:2n_g C6H6/s (b) The feed to a batch process contains equimolar quantities of nitrogen and methane. Write an expression for the kilograms of nitrogen in terms of the total moles n(mol) of this mixture. (c) A stream containing ethane, propane, and butane has a mass flow rate of 100.0 g/s. Write an expression for the molar flow rate of ethane, n_ Elb-mole C2H6/h, in terms of the mass fraction of this species, xE. (d) A continuous stream of humid air contains water vapor and dry air, the latter containing approximately 21 mole% O2 and 79% N2. Write expressions for the molar flow rate of O2 and for the mole fractions of H2O and O2 in the gas in terms of n_ 1lb-mole H2O/s and n_ 2lb-mole dry air/s. (e) The product from a batch reactor contains NO, NO2, and N2O4. The mole fraction of NO is 0.400. Write an expression for the gram-moles of N2O4 in terms of n(mol mixture) and yNO2 mol NO2/mol.