Question

Assume that the reaction for the formation of gaseous hydrogen fluoride from hydrogen and fluorine has an equilibrium constant of 1.15 X 10² at a certain temperature. In a particular experiment, 3.00 mole of each component was added to a 1.50 L flask. Calculate the equilibrium concentrations of all species.

Answer 1

           H2(g) + F2(g) ----> 2HF(g)

initial 3/1.5 = 2 M 3/1.5 = 2 M    0 M

change     x            x            x

equilibrium 2-x         2-x           2x

    K = [HF]^2/[H2][F2]

1.15 *10^2 = ((2x)^2/(2-x)^2)

x = 1.686

at equilibrium

[HF] = 2X = 2*1.686 = 3.372 M

[H2] = 2-X = 2-1.686 = 0.314 M

[F2] = 2-x = 2-1.686 = 0.314 M