Homework Help: Dan

Posted by Chem on Saturday, November 17, 2007 at 1:06pm.

N2 + 3H2 --> 2NH3

At 25°C (delta)Ho = -92.22 kJ and (delta)So = -198.53 J/K. Using this information, calculate the equilibrium constant for the reaction at 2.43x10^2°C. (R = 8.314 J/K)

Apparently the way I'm doing it is wrong:

I divide 198.53 by 1000 then multiply by 298 to get delta(S). Then I subtract this from delta(H) to get delta(G). Then I multiply 516 with .008314... I take this answer and divide delta(G) by it, then multiply by -1. I take this to the e power... Then I use the equation Kc = (RT)^-n * Kp to get the equilibrium constant. However my answer is still wrong.

Dan - DrBob222, Saturday, November 17, 2007 at 1:33pm
or mike or whomever,
Two points:
1. How do you know to calculate Kc instead of Kp? The problem doesn't specify which. Since this is a gaseous reaction, Kp may be what they are looking for.

2. Have you tried the van't Hoff equation. You have delta H and one T so the van't Hoff equation can be used to calculate K at any other T.

Answer this Question

Related Questions

Mike - N2 + 3H2 --> 2NH3 At 25Â°C (delta)Ho = -92.22 kJ and (...
Chem, help please - Consider the reaction N2 + 3H2 in equilibrium with 2 NH3 . ...
Chemistry - The following standard free energies are given for 25 degrees ...
Chemistry - Calculate Delta H for 4NH3 + 5O2 --> 4NO + 6H2O using: N2 +O2...
Chemistry!!! - Consider the rxn during the Haber Process: N2 + 3H2 ---> ...
Chemistry - Consider the rxn during the Haber Process: N2 + 3H2 ---> 2NH3...
Gr 12 Chem - Given: N2 + 3H2 = 2NH3 + 92.5 KJ, what is the delta h of f for NH3?
Chemistry - 2M +6HCl–>2MCl+3H2 Delta H= -638.0 Kj HClg—>...
Chemistry(Please help) - 1) Nitrosyl chloride (NOCl) decomposes at high ...
Chemistry(Please help) - 1) Nitrosyl chloride (NOCl) decomposes at high ...

For Further Reading

First Name:
School Subject:
Answer: