Answer:
Kc = 0,075
Explanation:
For a reaction:
A + B ⇄ xC + yD
Kc = [tex]\frac{[C]^x[D]^y}{[A][B]}[/tex]
For the reaction:
2 HI(g) ⇄ H₂(g) + I₂(g)
Kc = [tex]\frac{[I_{2}][H_{2}]}{[HI]^2}[/tex] (1)
In equilibrium:
[HI] = 1- 2x
[I₂] = x [H₂] = x
If 35,4% is dissociated:
[HI] = 1-2x = 0,646 ⇒ x = 0,177
[I₂] = 0,177 [H₂] = 0,177
Replacing in (1):
Kc = [tex]\frac{[0,177][0,177]}{[0,646]^2}[/tex]
kc = 0,075
I hope it helps!