Roll No: __________________
CL 152: Introduction to Chemical Engineering
Quiz-1 (Announced), 10th February, 2020
Duration 1 hour 10 mins
Total Marks: 20
Instructions:
1. Please return your question paper (writing your roll no.) with the answer sheet.
2. Weightage for numerical accuracy is 20%
3. This is closed book/notes pre-announced quiz.
1. Wet air containing 4.0 mol% water vapour is passed through a column with packing of
calcium chloride pellets which absorb 97% of the water but do not absorb any other
constituent of the air. The packing was initially dry and had a mass of 3.4 kg. After 5
hours of passing wet air, the pellets are reweighed and found to have a mass of 3.54 kg.
(a) Calculate molar flow rate (mol/h) of feed gas. [6]
(b) Mole fraction of water (vapour) in the product gas.
(c) If you run the process for a very long time, what will be the mole fraction of water
vapour at the exit?
2. Suppose you have a container with two inlets and one out let with variable cross section
(along the length). Liquid A and B are entering in that container and going out under
steady state condition. The properties of the fluids and the specification of the tubes are
given below. [4]
Diameter of the inlet tubes D1=2 cm, D2=3 cm and at the outlet D3=4 cm D4=2 am.
Density of the liquids, ρA=500 kg/m3, ρB=1000 kg/m3,
Inlet average velocities V1=2 m/s and V2=1 m/s.
Find out the average velocities at point 3 and point 4 and also the density of liquid C.
CL 152: Introduction to Chemical Engineering
Quiz-1 (Announced), 10th February, 2020
Duration 1 hour 10 mins
Total Marks: 20
Instructions:
1. Please return your question paper (writing your roll no.) with the answer sheet.
2. Weightage for numerical accuracy is 20%
3. This is closed book/notes pre-announced quiz.
1. Wet air containing 4.0 mol% water vapour is passed through a column with packing of
calcium chloride pellets which absorb 97% of the water but do not absorb any other
constituent of the air. The packing was initially dry and had a mass of 3.4 kg. After 5
hours of passing wet air, the pellets are reweighed and found to have a mass of 3.54 kg.
(a) Calculate molar flow rate (mol/h) of feed gas. [6]
(b) Mole fraction of water (vapour) in the product gas.
(c) If you run the process for a very long time, what will be the mole fraction of water
vapour at the exit?
2. Suppose you have a container with two inlets and one out let with variable cross section
(along the length). Liquid A and B are entering in that container and going out under
steady state condition. The properties of the fluids and the specification of the tubes are
given below. [4]
Diameter of the inlet tubes D1=2 cm, D2=3 cm and at the outlet D3=4 cm D4=2 am.
Density of the liquids, ρA=500 kg/m3, ρB=1000 kg/m3,
Inlet average velocities V1=2 m/s and V2=1 m/s.
Find out the average velocities at point 3 and point 4 and also the density of liquid C.
