CHE 202
Tutorial Assignment-8
Name:
Hassan Akran
ID:201830020
Problem 1: A solution of sugar in water is to be concentrated from 5 wt% sugar to 20% sugar.
The solution is at about 45°C when it is fed continuously to a bubble column. Air at 45°C with a
dew point of 4°C is bubbled through the column and emerges saturated. The humidification of the
air may be considered adiabatic.
Use the psychrometric chart to solve the following problems:
(a) What are the absolute humidities of the entering and exiting air?
(b) How many kilograms of dry air must be fed per kilogram of the entering sugar solution? What
is the corresponding volume of the entering wet air? (Use the chart for the latter problem as well.)
(c) Suppose that instead of feeding the air through a sparger (a device that resembles a showerhead
and releases the gas into the liquid as tiny bubbles), the air enters the column through a simple
pipe. Speculate on the probable changes that would occur in the two outlet streams and briefly
explain your reasoning.
Problem 2: Water is added to pure sulfuric acid in a well-insulated flask initially at 25°C and 1
atm to produce a 4.00-molar sulfuric acid solution (SG = 1.231). The final temperature of the
product solution is to be 25°C, so that the water added must be chilled liquid (T < 25°C), or a
mixture of liquid water and ice.
Take as a basis of calculation one liter of the product solution and assume Q = ΔH for the process.
If you need to know the heat capacity of ice, take it to be half that of liquid water.
(a) If only liquid water is added, what masses (g) of H2SO4 and H2O should be mixed and what
should be the initial temperature of the water?
(b) If a mixture of liquid water and ice is added, how many grams of each should be fed?
[Please Insert your solution here]