• University of Houston

• CHEE 2331

CHEE 2331 – Exam 1 – SP21

Academic Honesty Statement

At the top of your exam, write the following statement and sign your name:

I agree to abide by the UH academic honesty polices.

I will neither give nor receive outside help while taking this exam.

INSTRUCTIONS:

1) This exam is 4 problems and you will have 65 minutes. Please complete the exam on a

separate sheet of paper, tablet, or other writing device.

2) At the end of the exam, you will be required to upload all of your work to Blackboard

using the Exam 1 submission link. Submit your exam pages in order!

3) Clearly label and show ALL your work for all parts of the problems. Partial credit will be

given throughout. No work = No credit.

4) The work on this exam should be your work and yours alone. You are not allowed to

consult with peers, or to use online resources other than the eText, WileyPlus, and the

course Blackboard site.

CHEE 2331 – Exam 1 – SP21

1. [20 pts] A small fuel distributer is producing two products by mixing ethanol and

gasoline: E85 (85 vol% ethanol) and E10 (10 vol% ethanol). To meet demand, 80 liters of

E85 and 20 liters of E10 must be produced.

Gasoline is a mixture of various hydrocarbons. You can assume that gasoline has an

average molecular weight of 95 lbs/lb-mol and a specific gravity of 0.77.

a) [5 pts] Draw a flow chart and clearly state any assumptions.

b) [15 pts] How many kmols of gasoline must be fed to the process?

3 80L

Ms E85

g

0.85Vol1 E Assumptions

a 0.15Wl'tG steadystale

methane MsG mzX3 norms

MzE mz IXs

Mcgasoline G

Vy 20 L

MI EN

g

0.10volt E

0.90roil G

M4G m4X4

myE mallXa

b Approach

convertvolume of gas masswithdensity

and specific gravity

Gas In GasOut

p 5Gopwall kglL

m p.V

NoteBalancesarealways doneonmassor moles

Gasolinebalance

Mz MzG t M4G

v Vol't SG PW V Vol't SG PW

80L O ISN G 0.77711kgIL t 20110.90 G O77711kgIL

23 I kg

23.1kg 0.243knotgasoline

95k knot g­1

CHEE 2331 – Exam 1 – SP21