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Reg. No. : ..................................... Name : ..........................................
Third Semester B.Tech. Degree Examination, June 2009 (2003 Scheme) 03-306 – PROCESS CALCULATIONS (H) Time : 3 Hours
Max. Marks : 100 PART – A
Answer all questions. Each question carries 4 Marks. 1. How many kilograms of charcoal is required to reduce 3 kg of arsenic trioxide. As2 O3 + 3 C → 3 CO + 2 As. 2. An aqueous solution of caustic soda in water contains 20% NaOH by weight. Find the mole percent. 3. An aqueous solution of sodium chloride contains 28 g of NaCl per 100 CC of solution at 293 K. Express the composition in mole fraction NaCl. 4. Calculate the volume occupied by 6 kg chlorine at 743 mm Hg and 40° C. 5. What is meant by Boiling Point Elevation and Duhring’s Lines. 6. Why purging is used in processes ? 7. Explain the Trouten’s rule. 8. Describe what is meant by Theoretical Flame Temperature. 9. Explain the term limiting component. 10. Describe the term latent heat.
(4×10=40 Marks) P.T.O.
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PART – B Answer any one question from each module. All questions carry equal marks. Module – I 11. A liquefied mixture of n-butane, n-pentane, and n-hexane has the following composition in percent.
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n – C4 H 10 – 50 n – C5 H 12 – 30 n – C6 H 14 – 20 For this mixture, calculate a) The weight fraction of each component b) The mole fraction of each component c) The mole percent of each component d) The average molecular weight. OR 12. Absorbing chlorine in milk of lime produces calcium hypochlorite. A gas produced by the Deacon process enters the absorption apparatus at 740 mm Hg and 75° F. The partial pressure of Cl2 is 59 mm Hg and the remainder being inert gas. The gas leaves at 80° F and 743 mm Hg with Cl2 having a partial pressure of 0.5 mm Hg. Calculate, by applying the partial pressure method. 20 Module – II 13. In the concentration of orange juice a fresh extracted and strained juice containing 7.08 wt.% solids is fed to a vacuum evaporator. In the evaporator, water is removed and the solids content increased to 58 wt.% solids. For 1000 kg/h entering, calculate the amounts of the outlet streams of concentrated juice and water. 20 OR
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14. Soyabean seeds are extracted with hexane in batch extractors. The seeds contain 18.6% oil, 69% solids and 12.4% moisture. At the end of the extraction process, the residual cake is separated from hexane. The analysis of cake reveals 0.8% oil, 87.7% solids and 11.5% moisture. Find the % recovery of oil. 20 Module – III 15. A gas containing 80% ethane and 20% oxygen is burnt with 200% excess air. 80% ethane goes to CO2; 10% to CO; and 10% remains unburnt. Calculate the stack gas composition. 20 OR 16. Air is being compressed from 100 kPa and 255 K (where it has an enthalpy of 489 kJ/kg) to 1000 kPa and 278 K (where it has an enthalpy of 509 kJ/kg). The exit velocity of the air from the compressor is 60 m/s. What is the power required (in kW) for the compressor if the load is 100 kg/h of air ? 20
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