Chemistry
1I
ch 10
Homework
II
Name:
Sect.#
(1) Nickel hasa face-centered
cubicunit cell. Thedensityofnickei is 6.84g/cm3.Calculatea
valuefor the atomicradiusofnickel.
J, | -('tlt^1,^,1",,\(
r#;*)ffi#)
( slrf;
"/'
.2. 3.Fs,,o-(,.,-
6, l<.r, ua,4all-
*--(,t,f
-a""--
r, {6 z i.ti ,,itr^.,fO
:
c
l.jLrlD-'c-- = lSLf*
-:-:
(2) Titaniummetalhasa body-centered
cubicunit cell. Thedensityoftitanium is 4.50g/cm3.
Calculatethe edgelength of the unit cell and a value of the atomicradiusof titanium. (Note:
TheTi sphereswill touchacrossthe bodydiagonalof theunit cell)
ol=! , (zt,,4,^t/rr,,\(##r
_,\(+?)
= ,f.soJl I
T'
I,
3.al t, 1i?ro-
Fo. tr.<.c.un'] crllt
(,t,Y=x'+(t/r.Y
,,.[7.!
l/c
, t.!z^ti(r,--, tlLf.*',.
-=:
/'
=-
(3) Thenormalboilingpoint for acetoneis 56.5'c. Ifthe pressureis changedto 630
ton, what
wouldbethe newboilingpoint for acetone.(AH"uo- 32.0kJ/mol)
/^ ! , blt ( J - j)
(L
17r,
T,',
t?
l ^ ? L o J, 3 I ! _ / ! - :
?.3t.1 \ 'x
L3o
7t=X -' 7tl.rx ' fl'1"c
---=
--"---=:
\/
7z?'1
:-
(4) A substance
hasthe followingproperties:
=
AHuuo 20 kJ/mol C(s)= 3.0J/g'C
AH6 = 5 kJ/mol
C(l):2.5 I/g"C
Bp:75"c
C(g): 1.0J/g'c
Mp: -15'C
Sketchtheheatingcurvefor this substance
startinsat -50'C.
.r
,rhr-37 ft.l-2. slT.t
1
(.n. f , ,1, l,^"rl
-tf
E^.qJ
(5) How muchenergydoesit taketo convert2.5 g (Mw:74
problem#4 from a solidat -18'C to a gasat 75'C.
Q
t,
['
r a l a :=
. |t.sj)(","t/5".)(7'.).
\u '
,1L.5 J
"'']. n rL'L",' t(88J
7 t 1l--t
o
lrbT
g/mol)of the substance
in
z z . 55
=|
t.i.L,
-_---
= l{tl 7'
(6) Considerthephasediagrambelow. Whatphasesarepresentat pointsA throughH? Which
phaseis moredense,solidor liquid? Explain.
6 Li6e 6as
A tdu
fl toti/,Liylas H fohJ? 6o'
,
c LQ,i7
!J;,t ,s ^or" olr^s. II*^
[ryo;,!as d?,lul q lL,
D Lat
E {'av o"
,!"p"tcci4
. fr";J
F Sotitp {.iX;,,r
($ rl", ,('4t l,ni.
(7) A20.0 g sampleof ice at -10.0"Cis mixedwith 100.0g of waterat 80.0"C.Calculatethe
final temperature
ofthe mixtureassumingno heatlossto the surroundings.C(l) = 4.1SJ/g"C;
C(s)= 2.08J/g'C;AH6''= 6.02kJ/mol
?
u.o1 o{ it< 'lool 1o 6oc:
)
r c < 1 owrkr @ o " c ' .
-
@
(t
o)
7'- &o' b "8) "\' :lL !
3'
)
1oo1
4o f,ooelo 6"c:
loo x 4.1fft 90= 33'loor
7=
Fr^l pl,,n u,tt [" l4',t shr- @ >
'
@*@
7 a . o (.ttL = 6L7oJ
*
--t8,6
'lq + 6Qo+ (7l)('f.tr)(^-")
-?t",t.-(oo)(tlt)(x-?).=
?3,;^'
- (tUx-hvoo) = IL + 4:r.+ IL.LX
X: ff =l{zlt"c.l
(8) Somewateris placedin a sealedcontairidioffi?Gh to a vacuumpump(a devicewhich
lowersthepressureinsidethe container).Whenthe pumpis tumedon, thewaterappearsto boil
andthenfreeze.Explaintheseobservations
usingthephasediagramfor water.
-fu,a
on
P(1oil o.l. [) aa llao
f"*f , .(*".
6tlt ayu, 1, [,:1.c Jari: [,^,J. "rt, h,1hr.
"*.r,
l:LDDill
,Yr,",nlh""\
cca cu.r.,.lu,tl\
.lrn*".
cooltng
ll" [g,;"r Hro oLie^
(9) Using the heatsof fusion andvaporizationfor water, calculatethe changein enthalpyfor the
sublimationof water: HzO(s) - HzO(g).If the hydrogenbondin waterhasa strengtlof 21
kJ/mol, estimatewhat percentageofthe intermolecularforce in water is attributedto hydrogen
bondins.
Habq---it
tt&1b/*,^t
Ltlnh.' AHp,r o{v?'
ilgh,
1o, ll- 6.n/t (u l11o n/."l.
f H-Ut; !
)
lt- ks/^,,
n ta : fu/ .ruF $_.
It"t
ll-k^!t
(10) Doesit takemoreor lessheatto makea sampleof ice subiimethanto makethe same
amountof liquid watervaporize? Would the samebe true for dry ice?
fro^- *q
I
k--t
sr- lLrl nor'c [nrrS ;, AuloJ
1a,s^nful
bo ./rr. $t tor;
@ [al,--, t"il,-a|.,;-
Io,-,*n
[1
JrL[,,^o&>".
St^.+ CO4/) tl rtoi tl.lrL
is bbkru"ot.
(11) Diethyl etherhasa AHo"uo
of 29.1kJ/molanda vaporpressureof 0.703atma125.0"C.
Whatis its vaporpressrJeat 95.0"C?
l^ x , -21'oo_/
J - !)
tLt /
I
6.701 g.z..a
l
w
,n
_> :
6.1oi
Lz.j,l
-lLo
zft
X , ft = L.f? cl^
(12) Thecompounds
belowarecalled2-furoicacid,furfi.ual,andfurfuryl alcohol.
u
"-cl"
,-ot"/o
n
,' , - O - ' ^ a H
Y'-n
n
o"c1"--H
c:c
H
H
A
o"c1"--H
!-J
H
H
I
o'\c'H
t-J
H
H
C
a. Which ofthese compoundscanform H-bonds? Draw the H-bondedstructuresfor eachcase.
I
A
c<a^ul $r.,- F-L"n4
Y"-H.
L--zf
)=./
\z
o 1 +
H
"-(o-*'
E /
t--,
A
b. Someof thesemoleculescouldalsoparti"iput"ifo@'rolecular H-bonding.Draw theH\----"'
bondedstructures
for eachcase.
A
ll
,o-(o
\:-r
C
(13) Mn crystallizesin the samet)?e of cubicunit cell asCu. Assumingthattheradiusof Mn is
5.6Yolatgerthanthe radiusofCu andthe densityofcopperis 8.96g/cmr,calculatethe densityof
Mn.
dn^
-
,^q.tJ
3
?-"'-'"--
wl cr.It v .'
r
MtstCn x vol l ^
Jco.
=>
x Yol fl^
,n^
klmn
l
/vk,,-
VelCr
Y , ln n
-
,Y.q'l
A.f{
9
,/'9 )
l1.art
f r;l
,
U , o.tLd^/J\
(losu
)
e-
d(\^= o.a3'lJ c-
o'-7i.l
"(o-ttu11Y'r11
: [.fS ,f;
(14) The interiorvolumeofall unit cellsis comprisedof sphericalatomsandemptyspace.
Determinethe fractionof theunit cell volumethatis filled with spheresfor a simplecubiccell, a
face-centered
cell andfor a body-centered
cell.
fu fr, ,
tlr = tf.-
V f h * -' \" ,t
Ft*l,,^ o{ f,u",t ttc.-
j
1 ,f , r f
--t"--
1I , ( r )
3
-
3 0.7ta
<--
2t
f,*.rl<t caL"'I.{"'^'sl-
t'-'lL
(a,2 Lv
f.,"fL = 6.fLl
L"a" : O.L|b
ii".,