Sathyabama University 2008 B.Tech Chemical Engineering Chemical Process Calculation - Question Paper
SATHYABAMA UNIVERSITY
(Established under section 3 of UGC Act, 1956)
Course & Branch: B. Tech Chemical (Part Time)
Title of the paper: Chemical Process Calculations
Semester: I Max. Marks: 80
Sub.Code: 619PT102 (2007/2007 JAN/2008 JAN) Time: 3 Hours
Date: 17-05-2008 Session: FN
PART A (10 x 2 = 20)
Answer All the Questions
1. Find the moles of oxygen present in 500gm of O2. (Molecular mass of oxygen is 32).
2. State Raoults law.
3. What are limiting reactant and excess reactants?
4. Define relative humidity and absolute humidity.
5. What do you mean by material balance equation?
6. For the reaction C+O2 CO2, calculate the mass of O2 in grams required for 24 gms of carbon.
(Atomic weight datas : C = 12; O = 16)
7. Define Calorific value of fuel.
8. Write short notes about Orsat analysis.
9. State Kopps rule and Trountons law.
10. Define standard heat of reaction.
PART B (5 x 12 = 60)
Answer All the Questions
11. Sodium Chloride (NaCl) weighing 600Kg is mixed with 200Kg Potassium Chloride (KCI). Find the compostion of the mixture in (a) mass % (b) mole %.
( Atomic mass datas: K = 39, Na = 23, CI = 35.5)
(or)
12. Calculate the pressure exerted by 1 gmole of water vapour at 1173K and occupying a volume of 0.95 liter using (a) ideal gas law (b) Vanderwaals equation of state. Vanderwaals constants are:
a = 5.404 (lit)2 atm/(gm mol)2
b = 0.3049 (lit/gm mol)
Gas constant, R = 0.082 (lit.atm/gmol K)
13. Stock containing 1.562 gms of water per gram of dry stock is to be dried to 0.099 gm. For each gm of stock (dry basis) 52.5 gm of dry air pass through the drier, leaving at a humidity of 0.0525. The fresh air is supplied at a humidity 0.0152. Calculate the fraction of air recircuilated.
(or)
14. In the Deacon process for the manufacture of chlorine, a dry mixture of hydrochloric acid gas and air is passed over a heated catalyst which promotes oxidation of the acid. The reaction is 4HCL+O22CI2+2H2O. Air is used in 30% excess of that theoretically required. (a) Calculate the weight of air supplied per kg of acid (b) Calculate the composition by weight of the gas entering the reaction chamber.
15. The spent acid from a nitrating process contains 33% H2SO4, 36% HNO3 and 31% water by weight. This acid is to be strengthened by the addition of concentrated sulphuric acid containing 95% HzSO4 and concentrated nitric acid containing 78% HNO3. The strengthened mixed acid is to contain 40% HzSO4 and 43% HNO3. Calculate the quantities of spent and concentrated acids that should be mixed together to yield 1500 Kg of the desired mixed acid.
(or)
16. After a crystallization process, a solution of calcium chloride in water contains 62 parts of CaCI2 per 100 parts of water. Calculate the weight of this solution necessary to dissolve 250 Kg of CaCl2. 6H2O crystal at a temperature of 25C. Solubility of CaCl2 at 25C is 7.38 Kgmol of CaCl2 per 1000 kg of water.
17. A producer gas with composition by volume, 27.3% CO, 5.4%
CO2, 0.6% O2, 66.7% N2 is burnt with 20% excess air. If the combustion is 98% complete, calculate the composition by volume of the flue gases.
(or)
18. The exhaust gas from a hydrocarbon fuel oil fired furnace. Shows 10.2% CO2, 7.9% O2 and 81.9% N2 by Orsat analysis. Calculate (i) percentage excess air used (ii) Kg of dry air supplied per Kg of oil burnt in the engine.
19. Pure methane (1 Kmol) is heated from 303K to 523K at atmospheric pressure. Heat capacity is given by Cp = a+bT+cT2+dT3, where T is in K. Datas for methane are : a = 19.2494, b = 52.1135 x 10-3, c = 11.973 x 10-6 and d = -11.3173 x 10-9. Calculate the head added per Kmol methane.
(or)
20. Calculate the theoretical flame temperature of a gas containing 20% CO and 80% N2 when burned with 100% excess air both air and gas initially being at 25C.
Datas are: DH298 = -67636 Kcal
Total enthalphy of products,
SHp = 59.504T + 0.01125T2 1.484 x 10-6 T3 - 18703
Total enthalphy of reactants, SHR = 0
Enthalphy change DH = 0
| Earning: Approval pending. |
