Answer:
when the balanced equation for the reaction is:
H2(g) + i2(g)⇄ 2Hi
initial 0.5 0.5 X
-X -X +X
Final (0.5-x) (0.5-x) 2X
by substitution at the Kc formula:
Kc= [Hi]^2 / [H2] * [i2]
53.3 = (2X)^2 / (0.5-X) (0.5-X)by taking the square route
√53.3 = 2X / (0.5-X)
∴X = 0.39 m
∴[Hi] = 0.39 m