JNTU B.Tech I Semester Supplementary Examinations, November 2008
CHEMICAL PROCESS CALCULATIONS
(Chemical Engineering) SET-1
1. (a) A mixture of gases contains 10.5% CO2 13.0% Cl2 12.7% N2 and balance H2
i. What is the average molecular weight of the gas?
ii. Calculate the gas composition as weight fractions.
(b) Given a water solution contains 1.704 kg HNO3 per kg H2O and has a specific gravity of 1.382 at 200C, express the composition in the following ways
i. Weight percent HNO3
ii. Molarity at 200C
2. In the manufacture of HCl, a gas is obtained that contains 25% HCl and 75% air by
volume. This gas is passed through an absorption system in which 98% of the HCl is removed. The gas enters the system at a temperature of 490C and a pressure of 743 mm Hg and leaves at a temperature of 270C and a pressure of 738 mm Hg.
(a) Calculate the volume of gas leaving per 100 m3 entering the absorption apparatus.
(b) Calculate the percentage composition by volume of the gases leaving the absorption apparatus
(c) Calculate the weight of HCl removed per 100 m3 of gas entering the absorption
3. (a) Derive the Clausius-Clapeyron equation? What are the assumptions made in developing the equation? Explain, how it is used to calculate the vapor pressures of substances
(b) Write short notes on critical properties
4. Explain wet and dry bulb thermometry giving practical applications of the same.
5. A furnace uses a natural gas which consists entirely of hydrocarbons. The flue gas analysis is: CO2 – 9.5%, O2 -1.4%, CO – 1.9% and rest is N2. Calculate the following:
(a) the atomic ratio of hydrogen to carbon in the fuel
(b) % excess air
(c) the composition of the flue gas in the form CxHy
6. Methanol is produced by the reaction of CO with H2 according to the equation .
CO + 2H2 ! CH3OH
Only 15% of the CO entering the reactor is converted to methanol. The methanol product is condensed and separated from the un-reacted gases, which are recycled. The feed to the reactor contains 2 mole of H2 for every mole of CO. The fresh feed enters at 350C and 300 atm. To produce 6,600 kg/hr of methanol calculate
(a) Volume of fresh feed gas and
(b) The recycle ratio.
7. (a) Define sensible heat and latent heat
(b) Define heat of fusion and heat of vaporization
(c) Explain heat of condensation and heat of sublimation
8. (a) What is the heat of hydration.
(b) Differentiate between heat of solution and heat of salvation.
(c) Define standard integral heat of solution. How is it determined.
(d) Write on standard heat of combustion