Question: The equilibrium constant Kc for the equatino CS2(g)+ 4H2(g) goes to CH4(g)+2H2S(g) at 900 degree's C is 27.8. What is the value of Kc for the following equation 1/2CH4(g)+H2S(g)goes to 1/2 CS2(g)+ 2H2(g).

Question

I'm not sure what to do. the only thing i could think of was that it involved maybe the coeficents in some way?

Answer 1

Yes, it's the coefficients.
For example,
If the coefficients are doubled, then K for the new reaction is K^2
If the coefficients are tripled, then K for the new reaction is K^3.
If the coefficients are halved, then K for the new reaction is K^1/2 (sqrt K).
If the reaction is reversed, then K for the new reaction is 1/K.