JNTU II B.Tech I Semester Regular Examinations, November 2008

JNTU II B.Tech I Semester Regular Examinations, November 2008

CHEMICAL PROCESS CALCULATIONS

(Chemical Engineering)

SET-4

 

1. (a) How many moles of Sodium Sulfate will contain 200 kg of Sodium?

(b) How many kilograms of Sodium Sulfate will contain 100 kg of Sodium?

(c) What is Equivalent weight of a substance.

(d) Find the Equvalent weight of potassium Permanganate in the following reation

2 KMnO4 + 3 H2SO4 ! K2SO4 + 2MnSO4 + 3H2O + 5O

 

2. (a) Distinguish between an ideal gas and a real gas.

(b) 100 grams of N2 is stored in a container at 230C and 3 psig. Calculate the volume of the container.

 

3. Write briefly on the following:

(a) Cox chart

(b) Vapor pressure estimation using critical point.

 

4. The vapor pressure of styrene is 100 mm Hg at 82 0C and 200 mm Hg at 820C and

200 mm Hg at

100 0C. A gas that consists of 10 mole % styrene and 90 mole % non condensable

gas is at 100 0C and 1000 mm Hg. Calculate:

(a) The dew point of the gas

(b) The relative saturation

(c) The molal saturation and percentage saturation.

 

5. (a) Oxygen is mixed with air to produce oxygen rich air containing 75 mol% oxygen. In what ratio oxygen and air are to be mixed?

(b) A salt solution containing 25% of the salt with water as solvent sells for Rs. 200/- per kg. Another solution containing 12% salt sells for Rs.100/- per kg. What should be the selling price for a 17% salt solution?

 

6. Ethylene oxide is produced by the oxidation of ethylene over a catalyst. Safety considerations dictate that the gaseous mixture entering the reactor should contain 10 mol of air per mol of ethylene. The conversion per pass is 20%. The ethylene oxide formed is completely condensed out and the remaining gases recycled. The make up oxygen is added to maintain the requisite oxygen level. The reaction is represented by:

2C2H4(g) + O2(g) ! 2C2H4O(g)

For a plant producing 440 kg/h of ethylene oxide:

(a) Calculate the quantity of pure make up oxygen to be supplied.

(b) Calculate the ethylene in the make up stream.

 

7. Calculate the number of kcal required to heat from 500 to 15000C, 1 mol of a gas having the following composition by volume:

CO2 = 70%, N2 = 27% and O2 = 3%.

Cp for CO2 = 6.339 + 10.14 × 10?3 T? 3.415 × 10?6 T2

Cp for N2 = 6.457 + 1.389 × 10?3 T ? 0.069 ×10?6 T2

Cp for O2 = 6.117 + 3.167 × 10?3 T ? 1.005×10?6 T2

Here Cp is in Cal/(mol.K) and T is in K.

 

8. (a) Explain adiabatic reaction temperature.

(b) Obtain standard heat of formation of CH3Cl(l).

Data:-

? Hf for CO2 (g) = ?94058 cal

? Hf for H2O(l) = ?68317 cal

? Hf for HCl(aq) = ?40023 cal

? Hc for CH3Cl(g) = ?182810 cal

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