× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
5
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
Home Q & A Board Science-Related Homework Help Chemistry (Moderator: Laser_3)
New Topic  
smith0021 smith0021
wrote...
Posts: 18
Rep: 0 0
10 years ago
N2(g)+3H2(g) ---->2NH3(g)  DeltaH of the reaction= -91.8kJ

N2(g)+4H2(g)+Cl2(g)--->2NH4Cl(s) DeltaH of reation=-628.8kJ

NH3(g)+HCl(g)---->NH4Cl(s)   DeltaH of reation=-176.2kJ
Read 3611 times
1 Reply

Related Topics

Replies
wrote...
#1
10 years ago
This is very simple:

Multiply the third equation by -2.  The (-) will reverse the direction of the reaction.
Multiply the first reaction by -1.
Sum the modified first and third and add the second.  You will be left with
H2(g) + Cl2(g) ---> 2HCl(g).

Now perform the same operations on the DeltaH. e.g., third value times -2, first value times -1.  Add them now and add the second value.  That's it.

(-2)*(-176.2) + (-1)*(-91.8) + 1*(-628.8)
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  1281 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 274
  
 142
  
 65
Your Opinion
Which industry do you think artificial intelligence (AI) will impact the most?
Votes: 352
Previous poll results: How often do you eat-out per week?