Exam 3
*u"
Chem 1A
Watchunits and significantfigures!!
Returnthe card arter completingthe exam.
1. (22 pts.)
Multiple choice.
a.
U
9,
d.
b.
c.
d.
(v)
'
(vi)
s subshells.
dsubshells.
P subshglls,
f subshells.
2*.
How manyvalenceelectronsdoesthe carbonatomhave?
@4.
(iv)
Circlethe correctanswer.
The maximumnumberof electronsthat can occupyan energylevel describedby the principal
quantumnumber,n, is
a.
n.
b.
n '.
c.
2n.
@
(iii)
Showall work to receivefull credit!!
Transitionmetalelementshaveatomsor ions with partiallyfilled:
^s.
(i0
lfi) points
10 bonus points
October,20 2008
Dr.Somma
(i)
Y97
2.
6.
1.
Which of the following elementshasthe highestfirstionizationenergy?
a.
b.
c.
Na
Al.
TI
@
cl.
of a copperatomis:
Theelectronconfiguration
a.
tArl4s'4d.
b.
c.
d.
[Ar]4sr3dlo.
[Ar]4s23de.
none of the above.
Orbital energiesfor the electron in the H atom dependon which quantum numbers?
a.
@n.
n and l.
c.
tln l, fir and rn".
d.
n,l, andm,.
(vii)
Identify the transitionmetalion that is isolelecffonicto Fe*:
a.
b.
c.
d.
(viii)
Which of the following set of quantum numbersis (n,1, q and nr") invalid:
a.
(ix)
(4,3,-2,+ ll2).
A)
(3,0,-1,- uz).
c.
d.
@,2 ,-2 ,+l l 2 ).
(2 ,t,1 ,- l l 2 ).
Which scientistproposedthe wave-particledualityof matterin 19?z17
a.
b.
@
d.
(x)
Mn4*.
Al3*.
Mn2*.
Co*.
Einstein.
Bohr.
De Broglie.
Heisenberg.
The total numberof electronsthat canbe assignedto the n = 4 shellis?
a.
b.
"
(_y
d.
(xi)
8.
&.
^2 .
5
50.
Which of the following elementhasthe greatestmetallic character?
a.
b.
O
d.
Br.
Se.
Ni.
As.
2.(12pts.) The first ionizationenergiesof Li, Be, and C are 5.4,9.3 and 11.3eV. Keepingin
accounttheir electronconfigurationof theseelements,explain what you predict for the ionization
energyof B.
Li '. fue-lzs,
Be. fur)zs'
+ noilld#
B: Lile1r:,r::
( : ['(u ] 7t"?l'
.,. i,
;S e451cn { o
(1^t- s-rr&f]il.l-.Q
ti6*1Qs1t1"^^- ?'5n v
(+t *(
8e )
3. (12 pts.)a). What is the big differencebetweenthe energylevel diagramfor hydrogenandthat for
any multi-electronicatom? Hint Think aboutthe quantummechanicalmeaningof
"dggenerate'0.
7(1t or('iT-a!S ,ni'l'|aa.
*n
f^
h"*e^t^;
Ft>*(:*fuit
J*e
n pn-ncf"Q
ru,w-'{t+'t, n/
tr*
hn< kA< sq
io- ,"n/"tl'alocttttw.lea*6>,.5.n^^ eaoSz,r,ur^a)s o"o!:
tl -
encr)?
a^/-rbrWst
f>tc'taut
rn
&"u- a^1*kn
(J
l,
4r.t-!lv*nt''+t'6Lt,
ff
&f^4*q
s< ?re.6
b). What doesthe Pauli ExclusionPrinciple say?
A/o /.-r.r e|c'lana,l
f * fi@
4. (14 pts.)
i'\-
rlzt+ t*t-
h"'tX
e"\n"\
^1
{&-
Sa'""2 *4
{
n,/tna,As
n&>
a), How much energyis requiredfor an electronin a hydrogenatom to make the
transitionfrom the n=2 energylevel to the n=3 energylevel.
b). Whatis the wavelengthof a photonhavingthis energy.
c). Give fhe regionof the electromagnetic
spectrumin which the photonwill befound.
td '' r) (i - i)
,€ " - (z-ru<
= - (z.,g' rq:g (- o,,:r)
,l s .o :' /s - ' 1
a
D { = hu = ^y',^
,\:
c)
to8*y't\.
t4-eC,56' lo-? ,r.= | 6se
- (e.a.a.,o-tt3's\(3..00'
",*
T - G c)
Vrstbte.tblf
( n3,
*
(.,*).
5. (12 pts.)
Given that the positionof a hydrogenatom is known to within 1.00pm (picometer),
utilize the Heisenbergprincipleto computethe uncertaintyin the velocityof the atom.
Avn v.a x Z #
Av '6 x 7 h
A v ' (t.o o ,ti tzS
tl'4c4
>-
,to tl o
'"' ^^) 2
,o''O
(,'o'
Z
A V ' (l
6. (14 pts.)
rya- lcme.^> tul.:
*
3'lt r lo *'/s
a) Write the electronconfigurationfor the groundstateof the atomof cobalt(Co).
(pleasedo not usenoblegascoreabbreviations
for your answer).
b) Draw the orbital energylevel diagramfor a groundstateof Co (please,be sureto
labelthe orbitals)
c). CobaltcommonlyexistasCo3*ion. How doesthe diagramdrawnfor part b) haveto
be changedto representCo3*?Sketchthe changeto the right of the diagramdrawn for
part b); (please,be sureto labelthe orbitals).
Co'. IsLZs.ZpuSrr3yLlsr q 3d,'
4
r) -@-
{s -trl,_tdtllA
--- Sp
-T lLF
f ^F'I.rt1l}zs
-r1gzs
-t1]*
.)ra-w
;24e{sz;sG{f "s
W-,
7. (14 pts.) The elementBismuth(Bi, atomicnumber83) is the heaviestmemberof group5A. A
saltof this element,bismuthsubsalicylate,
is usedasactiveingredientof Pepto-Bismol@.
(Il)
a) The atomic radii of thallium
and Lead (Pb) are 148 A and 1.47A respectively.Using these
valuesand your knowledgeaboutthe trendsof atomic radii in the periodictable,predictthe atomic
radiusof Bi. Explainyour answer.
q6
)r"t tn^1 prrdt f
c. r6/n*t
6/ l,
45 afu>;z- ,*4t;
fr
4zc,<o**\1
Wq
(vqs t5\
sh,>"1/-
@ftrYa5,*tt"-
s^&&i
r4^r" *o
(
a'
--t-,r.et rrO{
f'8;
7L
b) Whataccountsfor the generalincreasein the atomicradiusgoingdown the group5A elements?
?oF,ilq,h\rn (
hror€ exfe^&cl dr6{Wg
tu k
n, Z, 3i (, ?, efc. 5tno&s.
c) This elementis alsousedasan ingredientin low- meltingmetalalloys.The elementitself is a britfle
white crystallinesolid.How do thesecharacteristics
fit with the fact that Bi is in the samegroupwith
nonmetallicelementssuchasnitrogenandphosphorous?
,f/^e
ctrn.ecdeaSlrbf
As n 4"t/^0t"v,(,
Ei shones ilrr
(
"w-1uh,-(
ivt €*tl,'?t
t{^g ebqta^ls
(y,t?.Sr-S e/^er.,44 ,^^t+-U'Z
o
sr',.'\-(
Qtl1trt 4t ;;
fr '*
J*F,
Tb 6< p.,A.f 4 * o-4GgCAMAz
t('
a
penTds
d) (BonusQuestion)BirO, is a basicoxide.Write the balancedchemicalequationfor its reactionwith
dilutenitricacid.
If 6i7 g of BirO, is dissolvedin dilute acidic solutionto make up 500 mL of solution,what is the
+ 3112O
E z.ql * tO-z,*( B;3t