page 1
Exam 2 - Form A
Chem201
Fall 2014
C,- 'U- pO
"1
'J­
1. What is the Ksp expression for copper(I1) phosphate?
2. Ifthe solubility of copper(II) phosphate in water at 25 DC is 1.7x} O~8 M, what is Ksp of
copper(II) phosphate?
(a)4.4 x lO- 16 (d) 2.8xlO~25
(b) 2.0xlO- 23
(c)
1.1xlO~2
C§O.sx10-37
Cv '1. C'PO " ") a..
(s)
~ ~'L..-
?--
.;..
2- (J 0
'1. ~-
~): 1< ~~ ~ CLv '1-~j3. [
-:: ('"!:> 'X ') 3.
3. f'O"1~-J 'l... 2-.x-) 'l..
• (
:;: What happens if~onijl is added to a saturated aqueous solution of copper(II)
phosphate?
(a) Nothing happens.
(b) The copper(II) phosphate solubility equilibrium shifts to the LEFT and more solid
dissolves.
(c) The copper(II) phosphate solubility equilibrium shifts to the RlGHT and more solid
precipitates out of solution.
(d) The copper(II) phosphate solubility equilibrium shifts to the LEFT and more solid
itates out of solution.
(e) e copper(lI) phosphate solubility equilibrium shifts to the RIGHT and more solid
ssolves.
.
c2 e
F\'"1.IV"1
xV' ev- \\1'.'\. e v'\.X
CD C'-'~ (~O ...)
wI
(J)
Iv ~.>
CN "\.-~
rx~
fr.,0.<-e-
®
Lv1
l~
C<.AM.\p\b'V
r-
~2A'
"'Q
~
en
L
5.
4..IJ
\
-< V\ a i..>.J
; c.c,...."U-
t-
~~
Cv.-"tA-.f?u ~l
~
2- rO '1"3,­
¥'~ } Lvut­
.l"'
'-(
C~'rl'-r
Cev... u
~
Cv.- ( tv ~ ~)..., 'Z-+
Cw'L+j J,..
rrlr) CD S,l.AlC+)
I'-' \~ 1
'1'­
~
J
t2. \G 1-1"\ rn
Exam2
Chem201
Fall 2014 4. page 2 FormA
What happens ifHN03(aq) is added to a saturated aqueous solution of copper(JI) 'l
phosphate?
S~j o..~ _~_~~_~[l!) N()!lllngMpl'ens.~~ ___~__~__~._._. _ _ .~. __
. _._.~_ . .__
(b) The copper(ll) phosphate solubility equilibrium shifts to the LEFT and more solid
dissolves.
(c) The copper(II) phosphate solubility equilibrium shifts to the RIGHT and more solid
precipitates out of solution.
(d) The copper(II) phosphate solubility equilibrium shifts to the LEFT and more solid
eciPitates out of solution.
(e
he copper(II) phosphate solubility equilibrium shifts to the RIGHT and more solid
Issolves.
~
o\..::::/
eu '3. ((#0'"1)
fO....,s-.;-
~ (j;)
5. b
C<. y<...-
('~ W',",
1....
(s)
~ Gv
-\
't,....J.-
':l­
'2 fO'-l.
.r
~<::..
H ()O'-1'L-
H3 0r
----?
\""I t-D.3,)
(~
1-\7..0
+--
h:., t~,J
Which one of the following combinations of iomc compounds would most likely result in a precipitate being formed?
6yol;il'(' ~ ~':l~vc;...)<" tc.l..lL - e>c:-f>Pc...\T>cJ.J-u '\(.)e.. [y:'Q '-(
'1-~.J.-.-
I
N
V\
CD
r- l G vt "1
$. IA., H--..l
C
(a) KCI(aq) + NaOH(aq)
--7
1"
f....J ....
-2(b) ZnCI2(aq) + N~SOiaq) ~, "2 \1\ ';.0"1 (Owift) r
C v!l"I~ -+-'Z.../-?..
AC)IKCI(aq) +
C/
AgNOg(aq)
'<-)
L
(d) NaN03(aq) + FeC12(aq)
Sv\~...r
0lV('/'
A;'C(
(..$.)
"':i-I /-1
L!>";~
Q.ve
0\>"\'
l'
-J I
Sot..... \Ole
~
K04 ("-'t') -I--
-I
~ Y.> ~
-t-
N~G\ lc.q,
c....rvvJ.~ ~~
o.:t
1<'
vIA. "I­
C~e~'; e;,e~
tn Io~ 1~\ .....""e..",
CA (&.t..)
1'2-
J
\ \Io'\..lQl .... ~\.e...
~(,t!'ft'lW'\
l\.J0J.
(c...'t.J
..s.()h-,~\~
\oUT ..s.\lVC!-v~7CCe.\OtI~_ _ _~
~h.cLw
01 \0 ~
s
Magnesium nitrate is dissolved in water to give a 5.0xlO- M solution. The pH of the ClYte o~
e.
solution is then increased by adding strong base. (Assume no volume change.) At what ~,: IS
pH will magnesium hydroxide start to precipitate? ~ of magnesium hydroxide
c ~ ......S (...
PlS (
6. "
loat" 0 n( d"\.­
5.6xlO- 12
kJ o.i) l-
~ p~l. ( o~) L~--:;::---~ c.. G\ Cc.~)
f..j
~5 (0"")1..-
" \... ~ .J..:lo\vb'e..,..
7. - - -..
page 3
Exam 2-Form A
Chem201
Fall 2014
. ._~. _
Fill in the blanks. Higher entropy in a system corresponds to _
system.
in the
----~.~ ~~:d~rder-~ .. -~. ~.
(c) greater energy
(d) lower energy
(e) greater energy and lower disorder
8. Which one of the following reactions most likely has AS 0< O?
(a) lis) .,. Ilg)
,otD<J~
') --?- :)
(b) NiO(s) + CO(g)
+X
ig) + 0lg) "" 2 N 20(g) ~
(d) N 2(g) + 02(g) "" 2 NO(g)
9.
~
.1
&;
~ 1.~
A<;;'<:\>O
~
ho ne.+
I Yl S.
C~Ot~e..
r~
Uv-
6S.;:)~O
Gft
(c) .
15 .r 1. j
Ni(s) + CO2(g)
\ V"c.V-e'Gl-e'..J
2
-71>
'2... (~)
~ ~ "2...-.5
. dJt c..""'("C \-('
o.\~O~
6S,J
~
\ y..,
~
d.lc..~C~~.,)
.", \
~
~
0
What is A8° for the following reaction? 8 ° ofN20(g) = 219.7 J/(mol-K); So ofH2(g)
130.6 J/(mol-K); 8 0 ofNH3(g) = 193 J/(mol-K); 8 0 ofH20(g) = 188.72 J/(mol'K)
N 20(g) + 4 Rig)
2l-'1n \"!>O.{..
(b) 167 J/(MIri-K)
(c) -)lJi(.!MJi-K)
(e) 31 J/(_'K)
fa";) -85.3/)')
H 20(g)
+X
19.?1L
-+--
L.f ( l ~ 0\
---
)' b
f:, ')
7
'-1
('2 SO~-tLO)
'2- \q. ')
-t
v/1<. l
\.) 'r"I ~v
10.
SOt-t'l.. ....
C:-~ "
A particular reaction has Mr > 0 and A8° > O. Which ofthe following is true about this
--­
t· ? reaClon.
6\-\ 'Mo....-e.. \"""~V"""~ ~ \ \,;'1...A..'..l...
D S>
f"'l';>~
\ \fV'lPOrh:;. ~
--t-- \A to'\........ I
(a) The reaction is favorable at all temperatures.
(b) The reaction is unfavorable at all temperatures.
(c) The reaction is favorable at low temperatures, but unfavorable at high temperatures.
@ ' h e reaction is unfavorable at low temperatures, but favorable at high temperatures.
~ \.0
<D
page 4
Exam 2 - Form A
Chern 201
Fal12014
Consider the following titration for the next 5 questions.
60.0 mL of 0.025 M C 6I1sCHzCOzH(aq) (in flask) is titrated with 0.040 M KOH(aq) (in buret)
~~~~~~~~_ _
11.
~
WfQ.j5-.~~ f>\c..lO_~~~~~_~~~_~~ _~~~~~_~~~~~~~ )~.b~_t\Je- _~~_~
What is the overall reaction occurring in the titration?
(a) C6H sCHzCOzH(aq) +
~6H5CH2C02H(aq) +
'-(c) C6HsCHzCOzH(aq) +
(d) C6H sCHzC02H(aq) +
(e) C 6HsCH2C02H(aq) +
12.
KOH(aq).... K[C6HsCHzC03H](aq)
KOH(aq) .... Hz0(l) + K+(aq) + C 6H sCHzC02-(aq)
KOH(aq) .... Hz0(l) + K(aq) + C 6H sCHzC0z{aq)
KOH(aq) .... K+(aq) + C6HsCH2C03H~(aq)
KOH(aq) --> H20(l) + C6H sCH2(aq) + KCO(aq)
What is in the flask afte 0.0
ofthe KOH(aq) solution have been added? (You need to calculate the eqwva en e point of the titration in order to answer this problem.) 'P\ F'! e:1'\.. e:C>t V\ vf');-L~ L C y.>'( ,
(a) C 6H 5CH2C02H(aq) and all products
(b) all products ((CpKOH and all products
(d) C~5CH2C02H(aq) and KOH(aq) ~) C 6H sCHzC02H(aq), KOH(aq), and all products @. e ~ 'I/'
...,...,..... b \
Ot. u t:l :=
VI c,., \
VoA1 e
~ C I?\
V\.?.,;. r;AV~ -:;C~
13.
:::
L(!. V
(l.
[O,D't-rr-.)( btJ,D ,....C) -;. ~~.r~L
-
= e'f:r\v,
y;>1->
( 0 o'"tcn'\-, \
How is the acid-base nature of the solution in the flask best characterized after 40.0 mL of
the KOH(aq) solution have been added?
l
~trong base
(a) buffer
(e) strong acid
14.
V Pi
(c) neutral
Lfab)-~eak acid
(d) weak: base
What is the pH of the solution in the flask after 40.0 mL
....., of the KOH(aq) solution have
@1.00
[b\-4
(> ~ .) -r t"" ~ U".l~ eo I"t 'E' "2 I r;- V'Y) L
been added?
(b) 3.00
-1 ':
-
(c) 1.40
(d) 12.20
[k () \.4 ~ eKt'...-~ '(Ylo\
\.-:::.D\.A ~)<:~
'::
{c
+0'\ V (e) 12.60
\<0\; )
(ab) 1.80
{Vl(OH.. . e>-\-.I;.\ t-o'\ \/""
~ (O\D'-tD~)CL,t;'VV'LJ
:::
1.0
)o<\O-1 M
(100 Y\L)
(\.o )<\O-'l.) ­
, 12,,, ~ <1 (, r - ~,o 0
15. Which of the following will be true at the equivalence point of this titration?
@H>7
5t",.,..+ 'w,\A....
\+- 5
CCf\'\~ v S
(.A.It" p..( <:.
1.0 4!'< l-{
(b)pH<7
W~ttJ.. . . .
cu::...
o.c;..,tJ.
\oe.- r f'
{!
(c)pH
I
W\\'\
@'tfU \. 0/,
~1."
-
7
t,-"",~ ... i-r...l t"'b
1-<.)l--'1<
<.A
c...vl II
\nt'"
~
Exam2
Chem201
pageS
FormA
Fall 2014
16. The answers
in order are .. ---:C-C.---...____- -..
_
.._ ..._ - (a) neutral, strong base
(b) weak base, neutral
(d) weak base, strong base ~eutrdl, weak base
- _.. -
17. .~.--
-.~-
(a) 0.17
\<" t
P\.(
t:..
~
tA..dc)... ~33
(b) 3.0
Cr H.-r w 1-\~":=
- \
~5
l
$"' I
't"<'« ... \
.( V7\A; - 10 k.e-'\
10'
(d) 5.9
~
PH ~
,
4.
'l-" ,.
\
t-
'9c..~
':;-
C!--
(e) 0.55 ,
_1'1->0
::: \ 1 0 at )c I 0
~ ~\
y: t 0
<w
\<\..;,.<t C,V\rtV
,C; b ) ,. 5 I 2 Z. I
~ W",::;)
C\
'::.
(q .1> -
crzq
L'J YIO-~
_­
.) \ l.L ')")
)0
§J
-= O\~3 0.
A buffer solution is prepared by mixing 5.0 mL of a 0.10 M solution of [CsHsNH]Cl
with 15.0 mL of a 0.15 M solution ofCsHsN. What is the pH ofthe buffer solution?
(a) 4.57
-=
(c) strong base, weak base
What buffer component ratio, b~/acjd, would be needed to make a pH 4.75 buffer out of
a mixture ofCsHsN and [CSH5NH]Cl? bose.
18. neLrr ,0-\. The conjugate
Fill in the blanks. The conjugate base of a strong acid is (a)
base of weak acid is (a) tvtAA.- be;: s e-
@.88
(c) 5.40
[C\ H $' tv -\-\-t J -;:
(d) 5.05
vn.oJ.. C) H rU \;f +-
(e) 4.17
:::
C
t-ut V
- (0 dO fY\)
D,,\~
( 5".0 ...... 1-) ~ O~OL) M
Yh ' )
l \ \.<::w.L)
2D -..<­
\ °d
I-llk.f ,.
h,,-tV "20 ...... L-­
(
C rH >
­
V
Chern 201
Exam 2 - Form A
page 6
Fall 2014
19. Citric acid is a triprotic acid, which for simplicity can be abbreviated H3Cit. What pH
range would a mixture ofH2Cir and HCie~ be best suited for making a buffer solution?
,..
-=-"I.
_ _00.77 to 5.}1.._ _.~_ .. ~__.-'-:..L. .C. .5_.4._.~0~_to-,-._7_.4...:...0_
(e) 4.77 to 6.40
\~
\c::.~
_ . _~~_.~_ ~~__~ (a)2.l1 to 4.13
(d) 3.13 to 6.40
e
..r Hz-O
1­
H'l0
-?­
C.." ,2>'­
r
\-\3 u +­
I. '-( yID-"1
~ ,\3
1,") >C'O-r
Y.77
'1.0 "1<'10-")
bt'10
\<.. a 2- ~ h-~ G,.;\ \.-., (" "" rt' p\.. 'v) f' c a.v.. K. \. .t- t c:J or rt! .> '(',..,.,...&A.. \-0 c cor r"-~
Co Y'\), "'.-:;....~ \.:::><!!. -.<.. ~A.\"""'.
'P \-\- V'" 6- V\~ \ (' ..t \ 0-(; 'P \«.::...
20. A buffer solution is prepared by adding 0.233 mol ofNaOH to 500 mL of a 0.20 M
solution of citric acid. What is the pH of the resulting solution? [Hint: The protons will
be removed sequentially, meaning that the first acidic proton will be removed to the
greatest extent possible, then the second acidic proton will be removed, to the greatest
extent possible and finally the third.]
(a) 2.82
(c) 5.07
/ (b) 6.70
(e) 4.47
,'­
o ,! 0
SOOML.x - - ­
to
\$1-0 v""\
1
0, \0
r
G,Vi, 0
'r \
0
is- (9 \01,3 ' \
&I09ot
= \f§J
Mul
t-.JA.OH
H2.-L \.r\­
-\- 0 \ t ~ t.Jc..O LI
'\t;
0, \0
lO(Ob6 -)
-::
+- 0,\
~
)
D H--::.
\-h C \. +
~o I
Vl'"! ..
1
I
\-\ C,'t
z...­
.It'OtO;]~ f......lao H
:7
~/~~~
\
~/// 0, 0 g,1 ~ Cit ~wl~
(, ~
0 .066. ~ H (\:t"'­
I efT-a
\.Ie"­
~~.
Exam2 FormB
Chem201
page 1
Fall 2014
L
Fill in the blanks. The conjugate base ofa weak acid is (a) (,..)eo-k
base of strong acid is (a) 'n e v .\vt::...t .
The answers in order are
(a) neutral, weak base
(J.9.)-'Weak base, neutral
(d) weak base, strong base
(e) neutral, strong base
~ ~ -~-~-~~ ~,-----
2. The conjugate
'~~~~~~- .... --.~- ... ---~
(c) strong base, weak base
What buffer component ratio, bas~acid, would be needed to make a pH 6.00 buffer out of
a mixture of C5HsN and [CsF4;NH]CI?
Y.5 edt
CA o...d.
(a) 6.6
(b) 3.0
(c) 0.17
&.9
(e) 0.33
~(!' ~
\0
o \4
I
"f u '('I-, ~ 'f", ,)
~ \O'I<~
L
::
L)
a.S~
~
3.
Io':::"l{
::
\
0
(
'\ e:~· -l.f>
f-u..,-, ~ \ 'r\~
:f+ \')
b,bO ­
~ ,'Li7)
""-""'­
-:
L{;]
q
~.
ba~e.
A buffer solution is prepared by mixing 5.0mL ofa 0.10 M solution of C5H5N with 15.0
mL ofa 0.15 M solution of [CsH5NH]Cl. What is the pH of the buffer solution?
C\.~'"
(a) 5.88
(b) 5.67
@.57
-:;.
lAGLOA -:;:.
[ c 5 kr t-..J \-\F! J
-::
(p.:, \
0
-­
(d) 5.05
yY\) (. ),0 _to..)
("2- 0.
rv--v~
V"-\
C:s- k
(e) 5.40
~
c--')
~ t-..J \A:-'r
"C.
(
I ), "'""-)
2--0 . VI-- ' ­
Cc
J
111
t.J l-\ -t
-t"'o"V
"'V
(0, I)" IY\ ')
0.07 r(V}
-:::;.
o , I 1 '7.. JV'1
'V
Exam2
Chem201
Fall 2014
4. page 2
FormB
Citric acid is a triprotic acid, which for simplicity can be abbreviated H 3Cit. What pH
range would a mixture of cif- and Hcif~ be best suited for making a buffer solution?
­-
..--..
--
_ ill1:77 to,~.77 ~_ _... ~~1QJ.()~.40 ___._..~
(e) 4.77 to 6.40
~ee
U~e. \<'~;1
t+ \ ~
A
'oec~~
c~~. .} ,
CO\f~cA
5. F-o f<.-n
lIT toV'"~~?~~
,
bet..H' ~t_
~C\..~
'ro ~
A buffer solution is prepared by adding 0.166 mol ofNaOH to 500 mL of a 0.20 M
solution of citric acid. What is the pH of the resulting solution? [This is a harder question
that you might want to come back to. Hint: The protons will be removed sequentially,
meaning that the first acidic proton will be removed to the greatest extent possible, then
the second acidic proton will be removed to the greatest extent possible and finally the
third.]
(c) 2.82
(b) 6.10
(a) 4.47
C; OD flAL
(d) 6.70
OI2-0~
X:
L
vf~ 2-"" A. 'f' \~ it
~l (' r"'vr-t"'\'f'....,......,.~
\{-t.-C \"t -
\0
H
\
-e
~.
0..
{fi)JS.07
",,A..
") ")
: L~ ,(l71
,..
\,"\
V"\
~
~
h
C
loS"
L
d- U'"
(01 Db£., \
La ,b~J)
I 0,
\0
~
t0o.0\-I
'\Y O,lO ",,",0.
41...C ,+­
1 0
~
,06b
f...j.t:{Di+
~
0\ Obb
~ H
0\ 0;"1
\ e.f-+
~
c;~
c.t""'2.­
\.-\Z.Clt­
page 3
Exam 2 - Form B
Chem201
Fall 2014
Consider the following titration for the next 5 questions.
60.0 mL of 0.025 M C 6IIsCH2C02{I(aq) (in flask) is titrated with 0.040 M KOH(aq) (in buret)
- G. eo-tA.
5~
_.__.~_. ~~: __~_ . . _.~. _&*OJ.'
~ __ .~ __.
.-.:-::s-..baR...
- .-..---.-~. .-.-.-.~
6. What is the overall reaction occurring in the titration?
(a) C6H sCHzCOzH(aq) + KOH(aq)
(b) C6HsCH2C02H(aq) + KOH(aq)
(c) C6H sCH2C02H(aq) + KOH(aq)
~6HsCH2C02H(aq) + KOH(aq)
&6HsCH2C02H(aq) + KOH(aq)
->
-+
->
-+
-+
H 20(l) + K(aq) + C6H sCHzCOz(aq)
K[C6HsCH2C03H](aq)
H20(l) + C6H j CHiaq) + KCO(aq)
K+(aq) + C~SCH2C03H~(aq)
H 20(l) + K+(aq) + C6H5CHzC02~(aq)
Whatisintheflaskaft~ 2theKOH(aq) solution have been added?
7.
(You
need to calculate the e~;nt ofthe titration in order to answer this problem.)
AP-"ICY\ eOu\ v i'rL~c...C 'PT
(a) C6HsCH2C0 2H(aq) and KOH(aq)
~~l products
(c) C6HsCH2 COzH(aq) and all products
~OH and all products
(e) C6HsCH2COzH(aq), KOH(aq), and all products
e~\V ..pJr
S,ee 8. ~
3 7 .. J'rV'L. \<....08
'Fo Y\. (VI f\
a.cJ
cl.t-A
~ \"2­
How is the acid-base nature ofthe solution in the flask best characteri7..ed after 40 ..0 mL of
the KOH(aq) solution have been added?
~ong base
(b) buffer
~~eak base (ab) strong acid
9. (d) neutral
What is the pH of the solution in the flask after 4.0.0 mL ofthe KOH(aq) solution have
been added?
(a) 12.2.0
See:
10. (c) weak acid
@1.00
'f-o ~ M
(c) 1.4.0
(d) 1.80
(e) 12.60
(ab) 3.0.0
A­
Which ofthe following will be true at the equivalence point ofthis titration?
(a)pH<7 ~-ft
fa
'(I-..M
(b) pH=7 _
~
~ 11
~H>7
Exam2-FormB Chem201
Fall 2014
11. page 4
Fill in the blanks. Higher Sthalpy in a system corresponds to ~ 1£~ in the
system.
-ell""le/Sr
~~_____ ~~~~_~ ______~~~ gIi~~~~~~disorder
~
eater order
(c ~ eater energy
a) lower energy
(e) greater energy and lower disorder
12. Which one of the following reactions most likely has ~s 0 < O?
(b) NiO(s) + cO(g)
&
Nig) + Dig)
+"
+"
Ni(s) + CO2 (g)
2 N 20(g) (d) N2 (g) + Oig) ... 2 NO(g)
13. What is ~So for the following reaction? So ofN20(g) = 219.7 JIK; So of Hig) = 130.6
JIK; So ofNHlg) = 193 J/K; So of H 20(g) = 188.72 JIK
N 20(g) + 4 Hig) ... 2 NH3(g) + H20(g)
UVl ~/
14. W./
A particular reaction has AIr> 0 and ~SO < O. Which of the following is true about this
reaction?
\)V\
(a) The reaction is favorable at all temperatures.
;(b))The reaction is unfavorable at all temperatures.
'(c) The reaction is favorable at low temperatures, but unfavorable at high temperatures.
(d) The reaction is unfavorable at low temperatures, but favorable at high temperatures.
page 5
Exam 2 - Form B
Chem201
Fall 2014
CM...1.,+-
PD '1~ ­
15. What is the ~p expression for copper(II) phosphate?
16.
If the solubility of copper(II) phosphate in water at 25°C is 4.8x 10- 6 M what is ~p of
copper(II) phosphate?
(b)4.4 x lO- 16 (e) 2.0xlO- 23
~.5XlO-37
x lO- 25
&.8
C U .3 C" 0
'1 )""},...­
-:F-
('j)
(c) 1.1xlO-2
~ G,.. .:1.-~Jr
::,'Y
(tt:..t)
-;,-
?- PO, C«..d
'2,~ \(6r ~ CCIA '2-rt~~ [ PD~ >- j '­
- (bY) ~ (2)c J 1­
--
Z.7>c'>~t;~'&.:;
-
\08'.><:>
b
\ 08' ( y .. g" ~ \ D- ) r -:;.
)it"';
~ ol..h.\,-':>
-15
'2
1
7~-/L\O
;:: )2. If' )ltD
17. What happens ifNa3P04(aq) is added to a saturated aqueous solution of coppertrI)
phosphate?
(a) The copper(II) phosphate solubility equilibrium shifts to the RIGHT and more solid
precipitates out of solution.
(b) The copper(II) phosphate solubility equilibrium shifts to the RIGHT and more solid
dissolves.
(c) The copper(II) phosphate solubility equilibrium shifts to the LEFT and more solid
dis olves.
(d) e copper(II) phosphate solubility equilibrium shifts to the LEFT and more solid
reeipitates out of solution.
(e) Noiling happens.
(j) Cu 'S (\?O't)-z;'
I\) c.J
(:l)
PO'1
c;~.--\
{
~
(:(r.J Le::Pl ,111
page 6
Exam 2 - Form B
Chem.201
Fal12014
18. What happens if ammonia is added to a saturated aqueous solution of copper(II) phosphate? ___~ __.._. _ _.~~ cOPJ!.~!..Q!lp119spha!~_solubiliJY~guilil::lJiJ!IDshifts to the RIGHTagd mQI:e solid
precipitates out of solution.
(b) The copper(ll) phosphate solubility equilibrium shifts to the RIGHT and more solid
dissolves.·
(c) The copper(II) phosphate solubility equilibrium shifts to the LEFT and more solid
dissolves.
(d) The copper(ll) phosphate solubility equilibrium shifts to the LEFT and more solid
precipitates out of solution.
(e) Nothing happens.
19. Which one ofthe following combinations of ionic compounds would most likely result in
a precipitate being formed?
&KC1(aq) + AgNO,(aq)
(b) NaN03(aq) + FeCI2(aq)
(c) KCI(aq) + NaOH(aq)
20. Magnesium nitrate is dissolved in water to give a 2.0x 10- 3 M solution. The pH ofthe
solution is then increased by adding strong base. (Assume no volume change.) At what
pH will magnesium hydroxide start to precipitate? K.p ofmagnesium hydroxide =
5.6x10- 12
.
M~ (c:n..n1.,..
(b) 8.15
(a) 4.28
(c) 3,48
[tv'. ~1-+ ~ C0\.", 3. "l.-
\<}( "
C0\" -'}" !~ ,b)<\ 0.
r 0 \.-t-
t2.
c
::::-
'('1-+ (d) 10.52
"'/L~j
D ,,\ 0''> • )
":
'(>
\
¥
()t 1'1 ,... I D -'J)
<-t, 1.7(;,(
1/1­
CD11":':, ~ (.'c: ,
~ ~""'~"'J)
~ ,1 q IO'S" L ~ CO"'-::] ~
c&~ Ix f"""'-v-
'--"--"
1
'L\
@.72 ~ \~.q"lb~ - 'i.i)b! ~ ~I~
.
£..,J\~o...A- ~c 'f'\ \- a....'"' II)
IV'5 (Ot1')"L
ADDITIONAL INFORMATION and EQUATIONS
Some K" Values at 25°C
K,,1
C6H sCH2 C02H
4.9 x1O- 5
H 3cit (citric acid)
7.4 x 10- 4
H 2C 20 4
5.6 xlO- 2
HC02H
1.8 x1O- 4
H3 P04
7.5 xlO- 3
6.2 xlO- 8
H2 SO4
very large
1.2 x 10- 2
HF
3.5 xlO- 4
4.0 xlO- 7
5.4 X 10-5
4.8 xlO- 13
Some Kn values at 25°C
Kb
xl0-~
NH3
1.8
HOCH2CH2NH2
3.2 xlO- s
CH3NH2
4.4 xlO- 4
CsHsN
1.7 xlO- 9
C6H SNH2
4.0 xlO- 1O
KaKb =
Kw =
1.008xlO- 14
[base]
pH "" pK + log-=-----=­
a
[acid]
Mr --
~LVlc
L...t
AGO -- L...t
~ AG 0
f products
L1
~=
- ~LVlc
f products
1.008xlO- 14
f reactants
L...t
-
~
L...t
AGf 0 reactants
R
8314xlO- 3 kJ/(mol'K)
0° C = 273.15 K