# 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-3

1. Oxygen is prepared according to equation 2 KClO3 !2 KCl + 3 O2. What is the yield of oxygen when 9.12 grams of Potassium Chlorate are decomposed? How many grams of Potassium Chlorate must be decomposed to liberate 2.5 grams of oxygen?

2. (a) Calculate the volume occupied by 30 lb of chlorine at a pressure of 743 mmHg and 70 0F.

(b) Calculate the weight of 1000 cuft of water vapor measured at a pressure of

15.5 mmHg and 23 0C.

3. An aqueous solution of NaNO3 containing 10 g – moles of solute per 1000 grams of

water, boils at a temperature of 108.7 0C under a pressure of 760 mm Hg. Assumingn that the relative vapor pressure of the solution is independent of temperature, Calculate the vapor pressure of the solution at 30 0C and the boiling point elevation produced at this pressure.

4. The weather bureau reports a temperature of 90 0F, a relative humidity of 85% and a barometric pressure of 14.696 psia: at 900F water vapour pressure=1.4215 in Hg

Antoine equation for water vapour pressure is given by log10p=7.3092- 1791.30 / T?35.05 Where p is kpa & T in k

(a) What is the molar humidity

(b) What is the humidity (Wt. basis)

(c) What is the percentage absolute humidity

(d) What is the dew point.

5. In burning toluene with 35% excess air, 15% of pure carbon deposited as soot on the walls of the furnace. Obtain the composition of the gases leaving the furnace.

6. A wet organic pigment containing 35 wt% carbon tetrachloride is to be dried to 4 wt% on wet basis. The drier is to operate adiabatically with fresh and recycled air entering the drier with 0.4 kg of CCl4/kg dry air. This air leaves the drier at 0.915 kg CCl4/kg dry air. The capacity of the drier is 198 kg dry solid per hour.Calculate the ratio of recycle to fresh air.

7. Write and explain:

(a) Watson equation,

(b) Kopp’s rule

(c) Kistyakowsky equation.

8. From the given data compute the adiabatic reaction temperature when 1 mol of gaseous chloroform at standard conditions reacts with theoretical amount of oxygen. Both oxygen and gaseous chloroform are initially at 250C. Standard heat of combustion of chloroform gas is given as ?121.8 kcal/mol. Mean molal heat capacities of  chloroform, oxygen, carbon dioxide, gaseous water and gaseous hydrogen chloride are given as 23.052, 7.293, 10.108, 8.215 and 7.0 cal/mol.K respectively

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

CHEMICAL PROCESS CALCULATIONS

(Chemical Engineering)-

SET-3

1. Oxygen is prepared according to equation 2 KClO3 !2 KCl + 3 O2. What is the yield of oxygen when 9.12 grams of Potassium Chlorate are decomposed? How many grams of Potassium Chlorate must be decomposed to liberate 2.5 grams of oxygen?

2. (a) Calculate the volume occupied by 30 lb of chlorine at a pressure of 743 mmHg and 70 0F.

(b) Calculate the weight of 1000 cuft of water vapor measured at a pressure of

15.5 mmHg and 23 0C.

3. An aqueous solution of NaNO3 containing 10 g – moles of solute per 1000 grams of

water, boils at a temperature of 108.7 0C under a pressure of 760 mm Hg. Assumingn that the relative vapor pressure of the solution is independent of temperature, Calculate the vapor pressure of the solution at 30 0C and the boiling point elevation produced at this pressure.

4. The weather bureau reports a temperature of 90 0F, a relative humidity of 85% and a barometric pressure of 14.696 psia: at 900F water vapour pressure=1.4215 in Hg

Antoine equation for water vapour pressure is given by log10p=7.3092- 1791.30 / T?35.05 Where p is kpa & T in k

(a) What is the molar humidity

(b) What is the humidity (Wt. basis)

(c) What is the percentage absolute humidity

(d) What is the dew point.

5. In burning toluene with 35% excess air, 15% of pure carbon deposited as soot on the walls of the furnace. Obtain the composition of the gases leaving the furnace.

6. A wet organic pigment containing 35 wt% carbon tetrachloride is to be dried to 4 wt% on wet basis. The drier is to operate adiabatically with fresh and recycled air entering the drier with 0.4 kg of CCl4/kg dry air. This air leaves the drier at 0.915 kg CCl4/kg dry air. The capacity of the drier is 198 kg dry solid per hour.Calculate the ratio of recycle to fresh air.

7. Write and explain:

(a) Watson equation,

(b) Kopp’s rule

(c) Kistyakowsky equation.

8. From the given data compute the adiabatic reaction temperature when 1 mol of gaseous chloroform at standard conditions reacts with theoretical amount of oxygen. Both oxygen and gaseous chloroform are initially at 250C. Standard heat of combustion of chloroform gas is given as ?121.8 kcal/mol. Mean molal heat capacities of  chloroform, oxygen, carbon dioxide, gaseous water and gaseous hydrogen chloride are given as 23.052, 7.293, 10.108, 8.215 and 7.0 cal/mol.K respectively