[Garibaldi]

I am currently working on a chemical equilibrium problem where I need to calculate K_p  for the following reaction:

N_2(g)+O_2(g)+〖Br〗_2(g)↔〖2NOBr〗_(g)

I am given the following two reactions, but I am unsure of how I am supposed to relate them to the main reaction:
〖2NO〗_(g) +〖Br〗_2(g) ↔〖2NOBr〗_(g)              K_c=2.0 @ 298°C
〖2NO〗_(g)↔N_2(g)+O_2(g)               K_c=  2.1×〖10〗^30  @ 298℃

[sjb]

Can you write your desired reaction in terms of the ones you know the Kc for?

[Garibaldi]

I suppose you could. I am not sure how to use those equations to solve for K)c.

[sjb]

If the Kc for the reaction A + B  C + D is x, what is the Kc for C + D  A + B?

Also perhaps look at http://www.google.co.uk/search?hl=en&q=relationship+between+kp+and+kc or similar?

[Thujone]

I am currently working on a chemical equilibrium problem where I need to calculate K_p  for the following reaction:

N_2(g)+O_2(g)+〖Br〗_2(g)↔〖2NOBr〗_(g)

I am given the following two reactions, but I am unsure of how I am supposed to relate them to the main reaction:
〖2NO〗_(g) +〖Br〗_2(g) ↔〖2NOBr〗_(g)              K_c=2.0 @ 298°C
〖2NO〗_(g)↔N_2(g)+O_2(g)               K_c=  2.1×〖10〗^30  @ 298℃

By flipping a reaction in the opposite direction you take the reciprocal of the Kc.  Notice if you flip the bottom reaction to O2 + N2<-->2NO, both 2NO's cancel out and the compiled equation becomes N2 + O2 +Br2 <---> 2NOBr.  Thus you can obtain the new Kc by multiplying (1/2.1E30)x 2.0