-Je,t lorl { r'^1t".*.
Name K?
Chem 1721/182L
Quiz 2 (20points)
l.
F e b r u a r y6 , 2 0 1 3
N x : 6 . 0 2 2x 1 0 2 3m o l - '
C: KP
A c o v a l e n t - n e t w osr ko l i di s m o s tl i k e l yt o b e
a. soft with a high meltingpoint,and a good conductor
c. soft with a low meltingpoint,and not a conductor
I r u r aw i t h a h i g h r n e l t i n gp o i n t ,a n d n o t a c o n d u c t o r
f|
\-/
d. hardwith a low meltingpoint,and a good conductor
e . n o n eo f t h e s e
2.
A scientistexaminesa sampleof an unknownsolid and determines
that it is brittle,hasa high meltingpoint,andrvhileit
doesnot conductelectricityin the solid state,it is conductivein its moltenform. This solid shouldbe classifiedas a(n)
a . m o l e c u l asr o l i d
b. covalent-network
solid
d . m e t a l l i cs o l i d
e . n o n eo f t h e s e
ionicsolid
G
C o n s i d e r t h e f o l l o w i n g i o n i c c o r n p oBu an O
d s, M
: gO,Csl,andBaS
W. h i c h o n e o f t h e s e r v o u l d y o u p r e d i c t h a s t h e
point?
highesrnrelring
4.
ioa. C-t1a'r'4e,
t^^:9q
J
pt g.uS
-fyvra{cr
-
Palladiumcrystallizeswith the unit cell shownto the right. The lengthof the unit cell
edgefor palladiumis 388.8^pm.Determine(a) the atomicrad.ius(in pm) of palladium,
(ingicm3)
and(b)thedensity
of palladium. fc c r.rn^t cel I, s o { = 1r/,1-z
(ror,.
a+u
nns)
€B ^ ,g1*P.*_f
a= (t Pnt
'-.-.,/
(3't8sxro-e.)3
= 131.5 prnn
-=----L--a
4=
5
t3-7.
5.
dn' ..
./
Yatrnno pcr cerl
38f.sP',=
H
3
M q 0
pm
1 . 6 L 1 xt o - t z l
=
- - - = - -J/rns
5. 8'l? xrO-2i,,,3 ta.oa
L
l -
u. u-
,4.0Q
g/crn3
Consider
thecompounds
labeled
A, B, and C shownbelow,thenanswerthe questionsthat fbllow
o
H2
Hz
ll
,,
^.ac'.t
^.ac:..^.-c-..^,,
n
a
u
U
U
U
n
'
H
2
H
2
H 2 H 2 H 2 H 2 H z H 2 H 2 H 2 ?
H-" CH
.c-2
C , cH- C 2
.c.C
.C.2
c . CH. c .2C . cH- O2H H 2
H , c2r C ,Hc . C2. c H
L
n2
Ho\^,,,c\^,,
U
n2
U
N
C
n0A'Prttal-
a.
Which one of these{A, B, orC} shouldbe the most hydrophobic?
b.
W h i c ho n eo f t h e s e{ A , B , o r C } w o u l dy o u p r e d i c ti s m i s c i b l ew i t h w a t e r ? p O t o *
c
For carbonmonoxidein water at25oC,the Henry's law constant,k: 9.5 x 10 a mol/L.atm. Determinethe partial
pressureof carbonmonoxiderequired(in atm) to reacha CO concentration
of 0.0831mol/L.
81 ,A-rn
that we havediscussed.Which one of tlrc
A metalin its pure (elemental)form crystallizesin one of the structures
with this metalhavingthesmallestdensity?
fbllowing cubic unit cellswould be consistent
1.
,i*nr. cubicunitcell
(?
b. face-centered
cubic unit cell
c . b o d y - c e n t e r ecdt r b i cu n i tc e l l
d. face-centered
cubic and body-centered
cubicwould resultin the samedensity
e. simplecubic and body-centered
cubic would resultin the samedensity
f. cannotanswerwithout knowingthe identityof the metal
8.
Considerthe unit cellsshownbelow,thenanswerthe questionsthat follow.
^
|
*
,}4*
k -- ***B
il
A panicleon a faceof unit cell A is sharedbetweenhow many differentunit cells?
b
Which one of theseunit cells {A, B, or C} represents
lattice?
a structurewith a close-packed
c.
What is the total numberof oafticlesin unit cell C?
d.
W h i c h o n e o f t h e s e u n i t c e l{l A
s , B , o r C } r e p r e s e n t s a l a t t i c e i n w h i c hlaalyl e r s a r e s t a c k e d d i r e c t l y o n t o p o f o n e
another?
9..
I
1 2 . 5 0g d i e t h y le t h e r( C a Hy s Om
, o l a rr n a s s: 7 4 . 1 2g l n o l , d : 0 . 1 1 3 4g / m l ) i s d i s s o l v e di n 8 7 . 5 0g c y c l o h e x a n o l
(C6Hr2O,molar rnass: 100.2g/mol, d : 0.9620giml).
a.
v
a
K1.fl7o
Detenninethe massoercentcvclohexanolin this solution.
V 1 . S i f r JC : o , t l , t z D I O D
x
/ oo- ooJ.ftta{ 'n^au
o.
, lbKb nsl
Determine
t h e a m o u n t( i n r r o l ) o f s o l u t ei n t h i s s o l u t i o n .
= o.ttoSL
tnol
la.sD_,
Q,+,oDx-4#+
1L+.ILJ
Determinethe molality of this solution.
' lb?lo w:.olsotu$ t .1e1 h' /t.-l
-==-r
ogl SD l$ sotwr*
ry =
d.
I06,\8,nL
Deterrninethe total volurneof this solution.
L.9A3 Cll$rsos t^LAtnj
1 H,.ox
f ? . 5 DQ
e.
= f ?.54 rnl-
vol = lDi.q&,rr.L
/.r#-u.0-
I n L / q u z o J= 1 o . 7 b n .
Deterrrt'ne
the molar concentration
of this solution.
r r,ll.Slorvrolsolrt*q
l '
r . 1 eylh
l
|
-
tDk+lI L sot;
= l . 5 5 4 u . oItg
/ . 5 5 q n o t fy
.
)
NameK+*l Pin'< { at u.
Chem172l/1821
F e b r u a r y6 , 2 0 1 3
N t : 6 . 0 2 2x 1 0 2 m
3 ol-'
C: KP
A m e t a l i n i t s p u r e ( e l e m e n t a l ) f o r m c r y s t a l l i z e s i n o n e o f t h e s t r u c t u r e s t h a t w e h a v e d iW
s chui cs hs o
en
de
. ofthe
with this metalhavingthe greatestdensity?
following cubic unit cellswould be consistent
Quiz 2 (20points)
l.
b . s i m p l ec u b i cu n i t c e l l
a . b o d y - c e n t e r ecdu b i cu n i t c e l l
0tu..-..nrered
cell
ctrbicLrnit
cubic and body-centered
cubicwould resultin the samedensity
d. face-centered
e. simplecubic and body-centered
cubic would resultin the samedensity
f. cannotanswerwithout knowinethe identitvof the metal
C o n s i d etrh e u n i t c e l l ss h o w nb e l o w ,t h e na n s w e trh e q u e s t i o ntsh a tf o l l o w .
A
t
s
t_
a.
What is the total nurrberof particlesin unit cell A?
b.
A particlein the centerof unit cell C is sharedbetweenhow many difTerentunit cells?
Which one of theseunit cells {A, B, or C} represents
a latticein which all layersare stackeddirectlyon top of one
another?
d.
3.
lattice')
Which one of theseunit cells {A, B, or C} represents
a structurewith a close-packed
A s c i e n t i set x a m i n e a
s s a m p l eo f a n u n k n o w ns o l i da n dd e t e r m i n etsh a t i t i s b r i t t l e ,h a sa h i g h m e l t i n gp o i n t ,a n du h i l e i t
doesnot conductelectricityin the solid state,it is conductivein its moltenform. This solid shouldbe classilledas a(n)
Aionic
c . m o l e c u l asr o l i d
b . m e t a l l i cs o l i d
solid
e . n o n eo f t h e s e
d. covalent-network
solid
2 2 . 5 0g d i e t h y le t h e r( C a H r e Om, o l a rm a s s: 7 4 . 1 2g l n o l , d = 0 . 7 1 3 4g / m l - )i s d i s s o l v e di n 7 7 . 5 0g c y c l o h e x a n o l
( C . , Hl 2 O ,m o l a rm a s s: l 0 0 . 2 g / m o l ,d : 0 . 9 6 2 0g / m | - ) .
a. Determinethe rnassDercentcvclohexanolin this solution.
11.5A "/"
xt00
b.
ar.saj (rH,oox ;*=*11.tzj
c.
= , 3-:0 3 Lm oI
3.1t1 ^o'lFJ
Determine
t h e m o l a l i t yo f t h i s s o l u t i o n .
vYt= .3 03b P.o|
d.
.303{, rno/
Determine
t h e a m o u n t( i n m o l ) o f s o l u t ei n t h i s s o l u t i o n .
= 9.1--:l7- ^''t l4J
l,a. l0rnnL
Determinethe total volulneof this solution.
*rcox
Jr. sD3C,,r
= 31.5Y
rnu
fti
: 80.5bnc
??.$_, CuH,,g, ln !
Determine
themolar."".."irttif{f
thissolution.
1 , y=' . 3 0 3 G , n o 1 .
.ll}l
\(
oL
-===-
.l0rnL
{ r f a . 1 ' I f l--_<
{'?
o $ m o t1 ,
5.
G
A c o v a l e n t - n e t w osr ko l i di s m o s tl i k e l yt o b e
b . soft with a high meltingpoint, and a good conductor
h a r dw i t h a h i g h m e l t i n gp o i n t ,a n dn o t a c o n d u c t o r
d . s o f tw i t h a l o w m e l t i n gp o i n t ,a n d n o t a c o n d u c t o r
c. hardwith a low melting point,and a good conductor
e . n o n eo f t h e s e
*
F o r c a r b o nm o n o x i d ei n w a t e ra t 2 5 o Ct,h e H e n r y ' sl a w c o n s t a n kt ,= 9 . 5 x l 0 m o l / L ' t t r t t . D e t e r l n i n teh e p a r t i a l
p r e s s u roef c a r b o nm o n o x i d er e q u i r e d( i n a t r n )t o r e a c ha C O c o n c e n t r a t i oonf 0 . 0 8 3 1m o l / L .
K1^hYl
7.
C o n s i d etrh e c o m p o u n d lsa b e l e dA , B , a n d C s h o w nb e l o w ,t h e na n s w e tr h e q u e s t i o ntsh a tf b l l o w .
o
H2
H2
ll
n
a
(
]
\C'l-\OH
n ^- 6 / " "Ht " ' z - 2
H
2
H 2 H 2 H z H 2 H 2 H 2 H 2 H 2 ?
n2
.H' " \ ^ r n/ " \ ^ , ,a
H"" CH. c2- CH, c 2- CH, c .2C ,Hc . C
c . C2 , cH. C2. cH. C 2, c -HC .2c . O H
2 .H
U
n2
a.
W h i c ho n e o f t h e s e{A, B, or C} would you predictis rnisciblewith water?
b.
W h i c ho n e o f t h e s e{A, B, or C} shouldbe the most hydrophobic?
: a O ,M g O , C s l , a n d B a S . W h i c ho n e o f t h e s ew o u l dy o u p r e d i c th a st h e
C o n s i d etrh e f o l l o w i n gi o n i cc o m p o u n d s B
Cs-f
lowest melting point?
9.
T
C
B
8.
U
P a l l a d i u m c r y s t a l l i z e s w i t h t h e u n i st cheol w
l n t o t h e r i g h tT. h e l e n g t h o f t h e L r n i t c e l l
( a ) t h e a t o m i cr.a d i u s( i n p m ) o f p a l l a d i u r n ,
e d g ef o r p a l l a d i u mi s 3 8 8 . 8p u r . D e t e r m i n e
and (b) tlredensity(in g/cmr) of palladium. fC C r^rt^t
ce ll; -[= tar/]-2
tl aforns
Fr
!.= 38E,8 yvn= \r/,tZ
{Aen F = (srg' 8'Pn)f tlE)
Ll
rc.al
d, **#{
"t=\e+D,,,r
d = 1.ob1x l6'zzJ
5. Ft?x l o'trcmt
r3?.5
r&f
i ;
r*d*r^r"*\
G"sss^rs;t-
= 1 3 r . l5---
a. r:
el
g
pm
b. d:
l.1.oa
3/cm?
----__
t a .0 e
.?. b
& '