GROUP WORK FOR EXAI'{ 2
CHMI52/54
l.
NAMES:
x 10-2 mol of CO, and 8.89 x
A 2.21 L vessel was found to contain 4.18 x 10-2 mol of CO2, 2.8I
I0-3
rmL oL lv r vo !f
a)
b)
the
2. Consider
the
rs jvr su fvFr rm.
reaction
no,
to
the
reactj-on
i.
proceed
to
N
dtl
L \ .2 /\ Y
+I
r?LH
! 2^
can be driven
and
fu ev l m
L yn
v eratrrrc
right
reaction
following
?
a \|
4 rlrrr 'r rj r r ./\ Y
^^"1Iihvirin
sYurarv
ae
q
t
hiah
at
f\ Ydt l
AHo
further
to
and Iow pressure
high temperature
and Low pressure
Iow temperature
.s /i \
!vw
and
fu cv r m
L L yn
e !c r : f r r r p
fotlowing
hiah
I o w i lnr nr Y
whic[
no,
to
the
left
=
+92.4
compl-etion
kJ
by using
of
conditions
at
equilibrium.
AH" :
+92'4 kJ
willto this reaction
of NHI (g) at equilibrium
the concentration
of H2(g) aL equilibrium
the concentration
fe h
c -V -d I-Urg' - ^ V^l c -L 'r r^V €^Y-u . ' i l i b r i u m
constant
rrC
reaction
to shifc to the right
has a pH value
of
5.48.
The IOH-]
concentration
for
7. A sofution which is formed by combining 200. mL of
of
a I OH-] concentration
following
b.
acids has the strongest
HC1O2
c.
HC1O3
solutj-on,
acid
solution
this
acid solution
6- The hvdronium-ion concentratlon of a 0.050 M lactic
acid
constant j-s 1.3? x 10-4. The pH of this lactic
dissociation
B. Which of the
HCJ-Oa
a.
rnr nv ru-,
equilibrium?
of a 0.010-mol-ar hypochlorous
4. The -hydronium-ion concentration
10-0 M. What is the pH of the solution?
5. A solution
JT !f
lr sc qe ec ut f- vi ^r rn. ?
nressufe
reaction
2 N H l ( g ) 3 N z ( g ) + 3 H z( 9 )
Adding Nz (g)
a) decrease
b) decrease
inere:se
ve )
t
d) cause the
fnl
nressgre
b)
c)
the
+hc
equilibrium.
rhr ri Ycr h
r
low
achieve
c)
a^ l t
3. Consider
€^F
Kc = 1.2 x I0-L3
2CO + 02
yes
This
Ts
must the
direction
2CO2:
O
v z" .
0.15 M HCI with
conjugate base?
HCIO
d.
HOCl, is
5.48 x
is
is 2.62 x 10-3. The acid
is
sofution
300. mL of
e.
0 . 0 9 0 M N a O Hh a s
HCl
is true with regard to a 0.030 M H2CO3 solution?
9. Which of the foltowing
c.
IHCO:-] > [ HzCol]
a.
IHzCO:] > [Ht]
t H ' l > [ H z C O l ]b .
e.
d.
ICOrz-' > [HCOI-]
Icorz-, > [HzCO:]
10. Which of the following
NaOHand HCI only
a.
d.
both a and b
11. Which of
KI
a.
the
followi-ng
b.
pairs of solutions
could
HF and NaF onl-y
b.
both b and c
e.
be mixed to produce a buffer?
c.
NH3 and NH4C1 only
salts when added to pure water
BaS
c.
NaCH3COO
will-
not change the pH of the
Na2O
e'
Lj-rSO4
d.
statements is
L2. Tn a sample of pure water, only one of the following
of temperature and pressure. Which one is afways true?
conditions
a)
c)
tHlotl :1.9
pH = 7.0
13. Cal-cufate the
x
I0-7 M
concentratj-ons
d)
of
always
Lrue ac af]
b)
toH-l = 1.0 x !o-7 M
pOH= 7.0
e)
[ Hto-] = t oH-l
H3O- and OH- ions
in
solution?
a 0.050 M Ba(OH)2 solution-
T 4 Dichloroacetic
acid is a weak monoprotic acid. A 0 . 1 0 0 M s o l u t i o n
0 . 0 0 7 0 M . W h a L i - s t h e v a l - u e o f K o f o r C I 2 H C C O O H ?T h e r e a c t i o n
i-s
+ H2O :
GI2HCCOOH
.rrarrlrf6
a)
I'l.
^H
Fr .
.v f
4.63
a
r c i d
h r e
.n3v I
solution
b)
that
4.14
is
c)
0.20
M in
NacH3coo and
4.95
d)
1.0
0.I0
5.05
x 1O-s. What is
M in
e)
the
cH3cooH.
5.22
I f 0 . 0 9 0 m o l e o f s o l 1 d N a O Hi s added to 1.0 fiter
the pH of the
o f 0 . 1 8 0 / r ' C H : C O O H ,w h a t w i l l
resrr'lI i no sol ution be? Assume no vol-ume chanqe due to addition
of NaOH. Ka(HOAc)= 1,8 x 10-s)
a)
lB.
fe h
6
r r v
f h i q
H:O- + C]2HCCOO-
weak acid, HA, is
15. The ionj-zatlon constant for the hypothetical
concentration
of I H3O'] in 0.20 /r' HA solution?
equilibrium
16
n f
4.51
4.74
b)
The mofar solubility
for BaCO3?
of
BaCO3is
19. One l-j.ter of saturated zinc
C a l c u l a t e K " O f o r Z n ( O H )2 .
2 0 . Magnesium hydroxide
M 9( o H )2 i s
10.49 at
2I
T h e v e l r r e o- -f "Ks-p-
22
T^ ^h ^e" . K. S p f o r
IO3- lons at
the following
solution
5.70
25oc. what is
contains
SrSO4 is
2.8 x 10-7. What is
is
2.L x l-0-20 at
e)
the
solubilitv
0.000222 g of
the pH of
the
dissolved
a saturated
the molar solubility
25oC. What is
5.94
of
molar
product
constant
Zn(OH)z
solution
of
SrSOa?
solubility
of
25" C?
Pe(IO3):
is
of
A precipitate
b)
c)
A precipitate
No precipitate
d)
No precipitate
e)
None of the
in
F- ions
saturated
1O-14. We mj-x two solutions,
25oC. At the instant
statements is true?
a)
25. Calculate
solution
d)
is a slightly
soluble substance. If
2 5 oC , c a l c u l - a t e K " O f o r M g ( o H ) 2 .
the concentration
24. Tine K"O for
5.08
9.0 x 1O-5 M at
hydroxide
maonesium arsenate
Mg3 (AsO4) 2 at
23. Calculate
-f o r
c)
of
mixing,
I Fel-1
CaF2 sol-ution
at
2509. Ksp = 3.9 x 10-11.
Fe3' and one containing
one containing
= 10-4 M and t IO:-] = 10-s g. Whlch one of
because 0"p > K"p.
forms, because O"p . K"p.
forms, because O"p > K"p.
forms, because O"p a K"p.
forms,
preceding
statements
is
true.
the precipitation
of ca]-cium fluoride,
the I Caz-, required to start
containing 0.0025 M E- aL 25oC. Ksp for CaF2 = 3.9 x 10-11
CaF2, from a
that is 0.30 Ir' in both Sr2t and Pb2-. Assuming no vo]-ume
26. Solid Na2So4 is added to a solution
at 25oC?
be Lhe t enz', at the point at which SrSOa just begins to precipitate
change, what witl
S -r S o. r = 2 . 8 x 1 0 - 7 a n d f o r P b S O 4= 1 . 8 x 1 0 - 8 .
-K. -s ,p -f _o _r _
ANSWERS:
't(r.6"1
x 1o-12),8D, 98, 1oE, 11A, 72E, 13 [ H:O']
L c , 2 8 , 3 8 , 4 ( 5 . 2 6 ' , , 5 ( 3 . 0 X l o - e ,) 6 ( 2 . 5 8 ),
=
8.1
1.4 x I0-3 M , I6D, t'tB, 18 b)
1
4
x
1
0-4 , 15 c)
1.0 x 10-13 //, IOH-]
0.10
b) 5.3
4.5 x IO-r7 , 20 e) 1.5 x 10-11
10-e , 19 c)
4 . 5 x L O - s M , 2 3 b ) 4 . 3 x 1 0 - 4M , 2 4 D , 2 5 d ) 6 . 2 x 1 0 - 6 M ,
5 . 3 x I O - 4 M , 2 2
, 2 I c )
26 dl
0.019 M
X