Name:
CHEM 1110.20787
Test 3, Form A
Spring 2013
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Part 1- Balancing equations and Stoichiometry Calculations (50 pts), show ALL work for credit.
1.
(6 pts) Balance the following equations and identify the reaction type.
a.
;2 AI + ~Ch ~ fl.,
AICh
Reaction Type:
CO ?nbina,h·on
Reaction Type:
deto7nf oS/-f1 0
n
2. (4 pts) Balance the following equations.
a.
_j_ Mg(N03)2
+
;<_
NaOH
~ _ /_Mg(OH)z + ;;2
NaN03
3. (10 pts) Write the balanced equation for the combustion of ethane, CzH6.
4. (10 pts) Allicin is the compound responsible for the characteristic smell of garlic. The molecular formula of
allicin is C6H100Sz. What is the mass of carbon in 3.45 g of C6H100Sz? (MM of C6H100Sz =162.27 gjmol)
5. (10pts) Automotive air bags inflate when sodium azide, NaN3, rapidly decomposes to its component
elements. What mass of sodium is formed when 15.0g of NaN3 decompose? (MM of NaN 3 = 65.01 gjmol)
~
:z
tJ())J?J ~ Ak .,.. 3 tJ~
J 5. ()dJo/tl~
? _7 Jola.
1m AlaN!!
J
~mol Ala
6
J50g NaN3x~)<
AI
. 0
~ 5. 0 JO 1./tuva ,1 mo I ;tla JV3
J
f. )).
j
~£_gO~ ;J~
qqj )lg,
mo
,.,.,
IV d.
6. (10 pts) The fermentation of glucose (C6H1206) produces ethanol (CzHsOH) and carbon dioxide. The
balanced reaction is below. What mass of COz is produced when 7.50 g C6H 1206 are fermented? (MM of
C6H1206 = 180.18 gfmol, MM ofCOz = 44.01 gfmol)
C6H1206 7 2 CzHsOH + 2 COz
f
""/. '>0 ~ 11120~
:' ?
CD.,_,
0
1m o 1 t, ~:v o, x .:1"""' co~
.x 180. I '3J
4/hA
/mol 4, t/j:J. ~
tf'fO~ CtJ7-- =Jrnoi"C 0 :Z..
Part 2 - Lewis Dot Structures, Molecular Geometry, VSEPR Theory, Hybridization and Polarity (40 pts) For
each of the following molecules or ions: draw the correct Lewis Dot Structure, determine the molecular geometry,
give the hybridization of the central atom and determine if the molecule is polar or nonpolar. Include all possible
resonance structures.
fr'4""A r [
: ()·
·.o:
•
·a
..
Molecular Geometry:
I t~..ncc.r­
Hybridization: _..S"'-t~'--a--,---.
Polarity:
nonftlla. r
JI
..
<--7 :o - s- 9:
J
••
~s-c;:;
·o·
J
<:-~> :o -s-==-
••
q
Molecular Geometry:
Hybridization:
Polarity:
..
:F.. /
.. 0..
'oLnf
_.S'"--1ff---7? ~-:::---f' o I a..("
~~.
r·
'
..
("
.
• t"'" •
Molecular Geometry: ~rt. ,::J/Q..fl.ttr
Hybridization: sp~d2.
Polarity:
nt>n Po La,~
I
IFs
Molecular Geometry:
Hybridization:
Polarity:
' '
:f
..
P<
..
Sf
;:L
fol a..c:
/f. --P:
"""-.
..
.' /
sr~~ f"'~~J. .. )
.~
. I .
Part 3- Bonding and Electronegativity (10pts)
1. (5 pts) How many sigma and pi bonds are there in the following molecule?
H ,~
H
~
~c--c
-1 t1
'
\ C=f1= C/,s
\eC--C
4f '/
H
'II ,
H--d~
\ s.
\,
H
H
~ It>
1':1-
C--H
\1 %c--c
so ~f
/ ,o
H
\ •e
H
H
2. (5 pts) Rank the following atoms in order of electronegativity: P, F, Cl, and Ge
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