Short Answer Practice
• Boiling water on your stove – batch,
continuous, or semi-batch?
• Write out overall material balance and
state which terms can be ignored for this
system
Chapter 4
Short Answer Practice
Ethylene (C2H4) reacts with oxygen to form
ethylene oxide (C2H4O) in a reactor fed
with 30 lb-mol of C2H4 and 30 lb-mol of O2.
Which reactant is limiting and by what
percentage is it limiting?
Chapter 4
Short Answer Practice
C4H8 undergoes complete combustion with
O2. If the stoichiometric equation is
balanced for this reaction, what is the
stoichiometric ratio of H20 to O2.
Chapter 4
Short Answer Practice
Why would you include a recycle stream in
a process?
Chapter 4
Short Answer Practice
Consider the pair of reactions:
A  3B + 2C
AD
B is the desired product and D is undesired. Suppose 100 mol A is
fed to a batch reactor and the final product contains 20 mol of A, 10
mol D, 210 mol B, and 140 mol C. Which of the following is true?
(a) This scenario is impossible.
(b) The fractional conversion of A is 0.20
(c) The percentage yield of B is 70%
(d) The selectivity of the reaction is 3:2
(e) b, c, and d are all true
Chapter 4
Short Answer Practice
Is the following scenario possible for a
reactor (Y or N)?
200 mol/h
100 mol/h
Reactor
50 mol/h
Chapter 4
Short Answer Practice
An unknown set of reactions takes place in
the reactor (see below). What is the value
of n3?
Reactor
100 mol CH4
233 mol O2
33 mol CH4
n1 mol O2
17 mol CO2
n2 mol H2O
n3 mol CO
Chapter 4