4.5 moles, each of hydrogen and iodine was heated in a sealed 10 L vessel. At equilibrium, 3 moles of HI were found. The equilibrium constant for `H_(2) (g) + I_(2) (g) rarr 2HI (g)`, is

Options

A. 1
B. 10
C. 5
D. 0.33

Answer

A

Explanation

Initial ` H_(2) + I_(2) hArr 2HI`
concentration `4.5underset(4.5-x) 4.5underset(4.5-x) 0underset(3(2x))`
`:. 2x = 3 mol`
`x = 3//2 = 1.5 mol e`
`4.5 - x = 4.5 - 1.5 = 3 mol e`
`:. K_(c) = [HI]^(2)/([H_(2)][I_(2)]) = (3/10)^(2)/((3/10)xx(3/10)) = 1 mol e//L`