NAME:
k!1J'
~
PERlOD:
CHAPTER 6 HOMEWORK
1. Calculate the kinetic energy of an object whose mass is 1.0 x 10.5 g and has a velocity of
2.0 x 105 Cm/S.
2
Vlr)1IT d.
z:
(. S) ( I. 0 )( 10- ~
) ( c2. 0 )( 10'"'
J<E ~ ~
~).,.1
:c
-*=J;:l
O,OdO
z:
(~q_.~-?~?j]
2. Calculate ~E for each of the following:
a. q = - 47 kJ, w = + 88 kJ
c. E
b. q
:: ~ 1--\,V = -
, ---·~·---~··---"l
( -<l1."k.:T J
i
'i 7)c:T
T
2-g.J:.:T
z:
'
= + 82 kJ, w = + 47 kJ
=
c. q = + 47 kJ, w
=0
)-_.
=
.(j7AcJ-j
----
.
0 :: [ ~ 7A.J /
d. In which of these cases do the surroundings do work on the system?
(a)
Ovvd
(b)
3. The equation for the fermentation of glucose to alcohol and carbon dioxide is
The enthalpy change for the reaction is: - 67 kJ. Is the reaction endothermic or exothermic? Is
energy, in the form of heat, absorbed or evolved as the reaction occurs? HEAT IS 810L'\fi::-D
(SUfo-~4~
4. Classify each ofthe following processes as either endothermic or exothermic:
a. the combustion of gasoline in a car engine
£ XOTr\82.VV\
Ie.
b. water condensing on a cold pipe E)(ol\-\ EJ<.M.
OVER
ie.
)
5. For the reaction
S (s)
+ O2 (g) ~ S02 (g)
Llli
=
-296 kJ/mol
a. How much heat is evolved when 275g of sulfur is burned in excess oxygen?
.s l- ",q~ J:.J
1 32.0f,j-3 Ilm~ S
1:.r = en :5,1 S J
/
t.
I "'~
.3
Cl. Sc.( XI()
=. d)S38p::
.1-;;-
b. How much heat is evolved when 25.0 moles of sulfur is burned in excess oxygen?
~I
~
·:>S.O_~ 3 \ "''fr,)a
I rn~ S
I
:: 7l/00
L~~,_'-!_~_~~O
)c.:T
J
j::..:r
~
\
c. How much heat is evolved when 150.0 g of sulfur dioxide is produced?
6. The specific heat capacity of silver is 0.24 JfCg.
a. Calculate the energy needed to raise the temperature of a 150.0 g block of silver from 273 K
to 298 K.
~~mC61
::
J
(/SO.Os
)(.
;:: 900 J
CJ.'-f
/9.
=
0
)(.;).5 C)
~
0
X
10 ,,;J.J
'7
b. Calculate the energy required to raise the temperature of 1.00 mol Ag by 1.0oC (called the
molar heat capacity).
x
~S,q
5-c
c. It takes 1.25 kJ of energy to heat a sample of pure silver from 12.0oC to 15.2°C. Calculate the
mass of the silver.
~ :: hi
I;)
~O
C~ T
::r ::: m (. d '-I
.::r
j
0e,
/.;;)so
(. ~t{)(3.J)
)(3. J L)
0
1
7. A 15.0 g sample of nickel is heated to IOO.OoCand dropped into 55.0g of water, initially at
23.0oC. Assuming all the heat lost by the nickel is absorbed by the water, calculate the final
temperature of the nickel and water. The specific heat of nickel is 0.444 JfCg.
b
/.f;LO
:.
3"It'
-
(Tf
(-ss.Oj('1.18tf)
T!
~ ..3o . /;;;Tf -
Q-30./d
-013.0)
--5.;)1;).
scq
..:?~o. Ie:;) Tf
-t-
J. •
i:
-
tro
::
7"
c.c:
::.
-
('.''''1 -
c. o c
=
Tf
(Tf
(tS,O)(.l./I.{L{)
If
of
S(;19:J.7"
J.3~. 1B-Tf:
~
-
100.0)
(P('('.O)
& ~. 0
-t-(p(,(,.O
stfS2.7"
-=----~----
L_T_I_=_.;;J __S ,_;;J
_Q
Zl--<I
8. When 1.50 L of 1.00 M Na2S04 solution at 30.0oC is added to I.sOL of I.OOM Ba(N03)2
solution at 30.0oC in a calorimeter, a white solid (BaS04) is produced. The temperature of the
mixture increases to 42.0oC. Assuming that the specific heat capacity of the solution is 6.37 JfCg
and that the density ofthe final solution is 2.00 g/ml., calculate the enthalpy change per mole
BaS04 formed.
,£Xon/ ~fY1 { e
Na2S04 (aq) + Ba(N03)2 (aq) -
~
~o-eJ;z;,'L ;;
~::.
BaS04 (s) + 2 NaN03 (aq)
(3tX1J
rj~
ao ~
L ') (J,
L)
z:
/J'lCl>T
(r,(J(J)) (~. 31 ) ( 4Q . 0 - .50, 0 )
z:
=
I. ,s() L
1s'ttt;<Jo
,j£l. 2.
2>0 q
J
I W\~
,Jq
l-
SOC(
II.-
I n".t ,&.sOC(
/ •• !~
J.4t SOt{
IL
=
J'OS7roO
9. In earlier times, ethyl ether was commonly used as an anesthetic. It is, however, highly
flammable. When five milliliters of ethyl ether, C4HI00 (I), (d = 0.714 g/mL) is burned in a
bomb calorimeter, the temperature rises from 23.SoC to 39.7oC. The heat capacity ofthe bomb
calorimeter is 10.34 kJf1C.
a. What is the q for the calorimeter~
~:: Co T
;; (10.
=
I~
~C)
3'-(
(e«
7, $of" Jc..J
7 ~C- .)~,
:-
s de)
7
L/6R..l-.:r
b. What is q when 5.00 mL of ethyl ether is burned?
c. What is q for the combustion of one mole of ethyl ether?
/mrr{
CqHto 0
7 'V. I
j(J
".s C 1-//
1/
7l(, /
s:
0
0
I (P
'-I #2l' 1<-.::r
.::
I
~.OOI>'\L
,
yY\
L
3l.{
s:
.7/t../j
~9 E»:
- (- 3,ifl
;--;;0
10. The enthalpy of combustion of solid carbon to form carbon dioxide is -393.7 kJ/mol carbon
and the enthalpy of combustion of carbon monoxide t form carbon dioxide is -283.3 kJ/mol CO.
Use this data to calculate m for the reaction:
2 C (s)
Cc:.")
~ co
+ O2 (g) - 2 CO (g)
+
O,;;}.
Cj) +
.;{ C (S)
~
O~~1
C(S)
-'7
+
-7
-'/
,;)o, Cj)
~
COaCj)
d
I..j")
CO;J
,;} COdl
Cj)
~
CO .2:1)
d CO(j)'"
OaCj) -~
- 3q3. 7 J:r
(.5)
d
O;;df)
~ CO Cj")
- ~ 9 3,3 .k:f
td...(
;::
- 7 ~ 7, L(
~Ii~
,98
I~~
z:
L---
kj-
e. 31. J
- S04. ( )c S-
l
JJ
11. Given the following data:
2 ClF (g) + O2 (g) - Cl20 (g) + F20 (g)
2 ClF3 (g) + 2 O2 (g) - Cl20 (g) + 3 F20 (g)
2 F2 (g) + O2 (g) - 2 F20 (g)
~H
~H
~H
= 167.4 kJ
= 341.4
kJ
= -43.4 kJ
Calculate ~H for the reaction:
ClF (g) + F2 (g) -
J. ell
r:: (j ) +
;)
~)
~
Ci 0 Cfj)
CJ
01
ClF3 (g)
o~
(,j)
001:5)
I-
F;.0 Cj)
3
T
CJ ~ 00 ) -I-
-"7
~
d
-=?
.;)
F;
0 fj )
6
J=""c20~)
Cl
r:;~)
.L
d
1~7.Y
t:.H::
0a 0 )
I-\.
s:
- ~
~~
0.4 J:.:r
b.t-+:
-3<-fI.Lfk:r
D.H:::
-Q/7.<..()C"J"
.--------------------~
c; F"~)
C.Q FtJ)
Fd~ )
d
4
oj.
t-.:l ~)
-7
;)
5 CJ)
Ci
C1 f;
-~
~--;;i7~J
~ I~ -
(5)
12. Given the following data:
P4 (s) + 6 Ch (g) P4 (s) + 5 O2 (g) PCl3 (g) + Cl2 (g) PCl3 (g) + Yz O2 (g)
-1225.6 kJ
~H = -2967.3 kJ
~H = -84.2 kJ
~H = -285.7 kJ
till
4 PCl3 (g)
P40lO (s)
PCls (g)
- Cl3PO (g)
=
Calculate ~H for the reaction:
P40lO (s) + 6 PCls (g) -
P<f 0,0
(5)
-"/
~ P C1 s ~)
10 ft!J.3 ~)
P4
(s) +- ~
-+-
10 ChPO (g)
P'f
(p
(s)
t
~4:: ,;;Q,,7. :3 Lo:
S O~(5)
f d 3 Cj )
+
0 Ci~(5)
sO ~ \1) ---;, 10 C}3 fOCj)
C~~~) -~
1PCi3
c I..J.=
01 ~.J-
() \~ = - d ~ S 7. 0 .k. «r:
6~
(.1)
SO.S.
=
-
OVER
---_._------
f d
a
S.
to
JeJ""
13. Use the values of ~Hfo in Appendix 4 to calculate ~Ho for the following reactions:
(a) Ca3(P04)2 (s) + 3 H2S04 (I) -- 3 CaS04 (s) + 2 H3P04 (I)
[s(- 14 ~.3) +
t.~ :
[-.;} ~ S .,kT
::
J - [( -
~ ( - ,~(,1)
=
L (-
+- 3 C-
s III ) ]
\
(b) NH3 (g) + HCl (g) -- NH4Cl (s)
b~
41~ G. )
3 I 4)] - [ (- 4 ~1 +
t-« ~ ) J
=
{-
Il ~.k- T
1
(c) SiCl4 (I) + 2 H20 (I) -- Si02 (s) + 4 HCl (aq)
Gt-+ ~ [( - q 1\ ")
z:
\ -
s
+ 4 ( - 1ft,1)]
3;,to.} r
- [ .(-~ 1')
+ d (- ;).~ (, ) ]
\
(d) MgO (s) + H20 (I) -- Mg(OH)2 (s)
6
L(- q ~ 5 ) J - [( -~
W~
0 d)
s:
+ (-
d K-~
F37.,tI 1
14. Using the values of ~fo
)
J
in Appendix 4 to calculate ~o
for the following reaction:
2 K (s) + 2 H20 (I) -- 2 KOH (aq) + H2 (g)
+0] - [0
01'+ -'" [Q(-4rr,)
+ d(
-~8''')] ~ ~
)c.~
Suppose a 5.00 g chunk of potassium is dropped into 1.00 kg of water at 24.0oC. What is the
final temperature of the water after the preceding reaction occurs? Assume that all the heat is used
to raise the temperature of the water.
~S
$,00-5
z:
K
1Fv\~
3Q.
D::
tJ1
K
:.
1°8 K
o/M~ ~
c s r:
;)'1 CloO
z:
(1000 )(t.f.
18q) (Tf
- ~C{.o)
.;)1(900
(1000) (t{,
I
(<<ft()
+ dl{
-
If
:::
»«
q.s
.s:
\
l!0' 0°c J