9. An acid mixture is to be prepared from (a) 99% H.SO., 1% H.O. (b) 95% HNO, 5% HO and (c) H20, if necessary. Determine. 0 The masses of (a), (b) and (c) to prepare 1000 kg of the acid mixture (40% H.SO.. and 20% HNO, and H2O). C) The mass of water which must be evaporated from 1000 kg of the acid mixture to produce a mixed acid of 66% H.SO4, 33% HNOs, and 1% H.O. () Calculate the average molecular weight of the acid mixture prepared in (1) and hence determine the composition in mole fractions and the amount of the mixture in kmol. All concentrations are expressed as wt%. 10. One thousand kilograms per hour of a mixture containing equal parts by mass of methanol and water is distilled. Product streams leave the top and the bottom of the distillation column. The flow rate of the bottom stream is measured and found to be 673 kg/h, and the overhead stream is analyzed and found to contain 96.0 wt% methanol. (a) Draw and label a flowchart of the process and do the degree-of-freedom analysis. (b) Calculate the mass and mole fractions of methanol and the molar flow rates of methanol and water in the bottom product stream. 11. Two aqueous sulphuric acid solutions containing 20.0 wt% H:SO. (p = 1139 kg/m) and 60.0 wt% H.SO. (p = 1498 kg/m) are mixed to form a 4.00 molar solution (p = 1213 kg/m). (a) Calculate the mass fraction of sulphuric acid in the product solution. (b) Taking 100 kg of the 20% feed solution as a basis, draw and label a flowchart of this process, labelling both masses and volumes, and do the degree-of-freedom analysis. Calculate the feed ratio (volume of 20% solution/volume of 60% solution). (c) What feed rate of the 60% solution (L/h) would be required to produce 1250 kg/h of the product? 12. A paint mixture containing 25.0% of a pigment and the balance water sells for 18.00/kg, and a mixture containing 12.0% pigment sells for 10.00/kg. If a paint retailer produces a blend containing 17.0% pigment, for how much (/kg) should it be sold to yield a 10% profit? 13. A liquid mixture containing 30.0 mole% benzene (B), 25.0% toluene (T), and the balance xylene (X) is fed to a distillation column. The bottoms product contains 98.0 mole% X and no B, and 96.0% of the X in the feed is recovered in this stream. The overhead product is fed to a second column. The overhead product from the second column contains 97.0% of the B in the feed to this column. The composition of this stream is 94.0 mole% B and the balance T. (a) Draw and label a flowchart of this process and do the degree-of-freedom analysis to prove that for an assumed basis of calculation, molar flow rates and compositions of all process streams can be calculated from the given information (b) Calculate the % of benzene in the process feed (feed to the first column) that emerges in the overhead product from the second column and (w) the % of toluene in the process feed that emerges in the bottom product from the second column. 14. A distillation column is used to separate an ethanol-water feed into a high purity alcohol and waste water. The feed has a composition of 20 mole % C,H,OH, the distillate contains 85 mole % alcohol and the bottoms have a 3 mole % alcohol concentration. (a) For 2.5 th of feed draw a carefully labelled process flow diagram. (b) Calculate the molar flow rates of the distillate and bottom streams. (c) What percentage of the alcohol is recovered in the distillate? (d) Determine the mass fractions of water in each of the input and product streams, page 2 of 8 Density of solution (10 kg/m) Volume% Ethanol Densities of Ethanol-Water Solutions at 20C Density of Weight % Volume% solution Weight % Ethanol Ethanol (10 kg/m) Ethanol 0 0 0.91322 51 1 13 0.91097 52 2 2.5 0.90872 53 3 38 0.90645 4 5 0.90418 55 5 62 0.90191 56 6 75 0.89962 57 7 8.7 0.89733 58 8 10 0.89502 59 9 112 0.89271 60 10 124 0.8904 61 11 13.6 0.88807 62 12 14.8 0.88574 63 13 16.1 0.88339 64 14 17.3 0.88104 65 15 185 0.87869 66 16 19.7 0.87632 67 17 20.9 0.87396 68 18 221 0.87158 69 19 23.3 0.8692 70 20 24,5 0.8668 71 21 257 0.8644 72 22 28.9 0.862 73 23 28.1 0.85958 74 24 29.2 0.85716 75 25 304 0.85473 76 26 31.5 0.1523 77 27 32.7 0.84985 78 28 339 0.8474 79 29 351 0.84494 80 30 36.2 0.84245 81 31 374 0.83997 82 32 38.5 0.83747 33 39.6 0.83496 84 34 40.7 0.83242 85 35 41.9 0.82987 86 36 0.82729 87 37 441 0.82469 88 38 452 0.82207 89 39 463 081942 90 40 47.4 081674 91 41 4843 0.81401 92 42 49.51 081127 33 43 505 080848 94 44 51.6 080567 95 45 526 08028 96 46 537 0.79988 97 47 547 0.79688 98 48 958 0.79383 99 49 36,8 0.790974 100 50 578 0.99813 0.99629 0.99451 099279 0.99113 098955 098802 0.98653 0.98505 098361 098221 9.98084 0.97948 0.979448 9.97687 0.97687 0.97431 0.97301 0.97169 0.97036 096901 0.96763 0.96624 0.95483 0.96339 0.9619 0.00037 09588 0.95717 0.95551 0.95381 0.95207 0.95028 0.94347 0.94662 0.94432 0.94281 0.94086 0.93886 093548 0.93479 0.93272 0.93062 092849 092636 0.92421 092204 091986 0.91766 0.91546 598 80.8 618 628 638 548 658 668 677 68.6 699 705 715 724 73.3 742 75.1 76 76.9 778 786 79.5 B04 812 82.1 838 84.6 85.4 862 871 879 88.7 895 90.2 91 91.8 925 932 94 947 954 96.1 967 974 98.1 987 993 100