Basic principles & calculations in chemical engineering

question #1 (3.1.9 ) :-

in the making a material balance, classify the following processes as (1) batch, (2) semi-batch, (3) continuous, (4) open or flow, (5) closed, (6) unsteady-state, (7) steady-state . more than one classification may apply.

a. a tower used to store water for a city distribution system

b. a can of soda

c. heating up cold coffee

d. a flush tank on a toilet

e. an electric clothes dryer

f. a water fall

g. boiling water in an open pot

 

 

question #2 (3.1.12) :-

100 kg of sugar are disolved in 500 kg of water in a shallow open cylindrical vessel. after standing for 10 days , 300 kg of sugar solution are removed. would you expect the remaining sugar solution to have a mass of 300 kg ?

 

question #3 ( please see attachment ) !!!!!!!!!!!!

 

question #4 (3.2.9) :-

three gaseous mixtures, A,B & C , with the compositions listed in the table are blended into a single mixture

Gas     A       B       C

CH4    25     25      60

C2H6  35     30      25

C3H8  40     45      15

total    100   100    100

 

A new analyst reports that the composition of the mixture is 25% CH4 , 25% C2H6 , and 50% C3H8 . without making any detailed caculations , explain how you know the analysis is incorrect ?

 

question #5 (3.2.14 b ) :-

for the following problem :

1- draw a figure

2- put the data in the problem on the figure

3-pick a basis

4. determine the number of unknowns and independent equation

5-write the material balances needed to solve the problem

6- write down any other pertinent equations and specifications

7-solve the problem if possible

 

(b) a dryer takes in wet timber ( 20.1% water ) and reduces the water content to ( 8.6% ) . you want to determine the kg of water removed per kg of timber that enters the process .

Solution: