A mixture of H2, S, and H2S is held in a 1.0-L vessel at 90°C and reacts according to the equation

Question

H2(g) + S(s) H2S(g).
At equilibrium the mixture contains 0.46 g of H2S and 0.40 g H2.
(a) Write the equilibrium-constant expression for this reaction (Kc).

I got Kc= [H2S]/[H2]
but the online homework program says its wrong

Answer 1

the reaction is
H2(g) + S(s) <--> H2S(g).
forgot the arrow

Answer 2

Thanks for the arrow. Instead of going through the problem I'm going to take a guess as to what you did wrong. I'll bet you didn't convert g H2S and g H2 to mole/1.0L and substitute those numbers.