Homework Help: Chemistry

Posted by Taylor on Wednesday, June 30, 2010 at 9:13pm.

Calculate Delta H for 4NH3 + 5O2 --> 4NO + 6H2O
using:
N2 +O2 --> 2NO DH= -180.5 kJ
N2 + 3H2 --> 2NH3 DH= -91.8 kJ
2H2 + O2 --> 2H2O DH= -483.6 kJ

Chemistry - DrBob222, Wednesday, June 30, 2010 at 9:28pm
Hess' Law.
Multiply equation 2 by 2 and reverse it.
Multiply equation 3 by 3 and leave as is.
Multiply equation 1 by 2 and leave as is.
Add the resulting equations.
Add the resulting delta Hs also, (after multipling AND changing the sign of those reversed.

Answer this Question

Related Questions

Chemistry - The following standard free energies are given for 25 degrees ...
Chem - Please tell me if these are right. 1.According to Le Chatelier’s ...
PLEASE HELP Chem - Please tell me if these are right. 1.According to Le ...
Chemistry - Under the appropriate conditions, NO forms NO2 and N2O: 3NO(g) &...
chemistry - Under the appropriate conditions, NO forms NO2 and N2O: 3NO(g) &...
Finding Delta G - The following reactions are important ones in catalytic ...
Chem II - Kp < Kc at 25 degrees C for which of the reactions below? N2 + ...
chemistry - Use Hess's law and the following equations to calculate ÄH...
Chemistry - How do I find the equilibrium constant for 4NH3(g) + 5O2(g) --&...
chemistry - Calculate the delta H for the reaction N2H4(l)+ O2(g) --> N2(...

For Further Reading

First Name:
School Subject:
Answer: