Name
ilHrxn Problems
(I) Find the ilH for the reaction below, given the following reactions and subsequent
values:
PCIs(g) -+ PC1)(g) + Cb(g)
P4(s) + 6Cb(g) -+ 4PC1)(g)
4PCIs(g) -+ P4(s) + IOC\z(g)
L./
PU?
-::,;J
PLi +
L\ r"rfl"-t"
-L-(
1.0
'-/
'5
+
'l',Vi: I
ilH = -2439 kJ
ilH = 3438 kJ
'-(
~
~
~ J<
0)2
- 2 L./
d3
L{
/J
3Cf ~J
3Ll3B
lDU,
-I-
-/
to-z...
qqq
=.
-+- L.l PCP3
c'
t. ~-
iL.t
li
Lj-
Pc.P3
+-
(2) Find the ilH for the reaction below, given the following reactions and subsequent
values:
2C02(g) + H20(g) -+ C 2H2(g) + 5/202(g)
C2H2(g) + 2H2(g) -+ C2H6(g)
H20(g) -+ H2(g) + 1/202 (g)
C2H6(g) + 7/202(g) -+ 2C02(g)
(1
I
I
-'7.1
1...'2 -H U
O 2...
2C 07
~
~
~~
1
1
')
...:::;
tr
-3H;L
7
~--
I
I.
i
'Z..
+I U 0 ~
-
10.02
C/li,
f} X7 it
+
1 (
-'
2.
f I",-
.-'
'6
"':?
~
235.'1 -/
M;:--U~O li6c Ae
-'7
7
fVz.'
H &.-l
.IV1:
-t
C-~.-e-
N2- 1-/ t..f
C~
f
-7
~lJtit J-5~jJ,~
l-JL
+-
f}{
t
2 N-Jl?...-J
~'.
t-
t-
l+z.
cJ:krC}
__ .-------
.
ilH
ilH = -37 kJ
ilH = -46 kJ
ilH = -65 kJ
+ N2(g) + 3H2 (g)
c..M?1J
H...=..-
@3<5 KJ 1
(3) Find the ilH for the reaction below, given the following reactions and subsequent
values:
N2H4(1) + H2(g) -+ 2NH3(g)
N2H4(1) + CH40(l) -+ CH20(g)
N2(g) + 3H2(g) -+ 2NH 3(g)
CH40(l) -+ CH20(g) + H 2(g)
ilH
ilH =-94.5 kJ
ilH =71.2 kJ
ilH =-283 kJ
+ 3H20(g)
'
II'
Z H'"2-
ilH
-37
-LI ["
+-&6 .
(ift+",,"
-1"8 Kl \
(4) Find the ~H for the reaction below, given the following reactions and subsequent
~H values:
H2S04(1) -t S03(g) + H20(g)
H2S(g) + 202(g) -t
H2S(g) + 202(g) -t
H20(I) -t H20(g)
C2H60(I) + 302(g)
C2H40(l) + 5/202(g)
2C'2/-1qO
'71-12. Q
r
-r
L C-1-ttL-lOt-
~H
~H
~H
H2S04(1)
SO 3(tD + H20(1)
-t
-t
2C02(g) + 3H20(1)
2C02(g) + 2H20(l)
+
-7 ~
.~
~
;:')
21--1;:-.0 - -/
;0 2-
Oz
-235.5 kJ
= -207 kJ
= 44 kJ
=
~H = -685.5 kJ
~H = -583.5 kJ
!1!-1~ :;; .• -5~3.SJt
~
~
-I-
LC"2,. +ill 0
2C.:z. H
1\
l-l :: ;p. f (p 3 c!>. 'S
-ltI.5.0 ~J//'YI~ -t
SiCs)
+ 2F2(g)
.j60.0~!
1,
8) SiF4(g)
-t
Si(g)
.
x
n.-~
+ 2~2(g)
+ 3H20(l)
+- 20 ~t)1 0 ~
_£/3~1~
-118,1 y..J/yY'-~ ,.:Z1;?I'B
10) 3K202(S)
+- I i.e 16.D t-J
~i\~c;) ~ ~'Cj)
-t
6KOH(aq)
J
~-O-._- @H -=.1'2.0~.O@
Use the heat of formation values that are found in the appendix of your textbook to
determine the ~Hrxl1 for the following.
7) SiF4(g)
IL
/'-12,(
+ 03(g)
-
15'I~lJt
-
-
-luI6.O
-0-