Posted by
**Janna** on
.

X2 + Y2 <=> 2XY

0.50 mole each of X2 and Y2 are placed in a 1.0 litre vessel and allowed to reach equilibrium at a given temperature. The equilibrium concentrations of XY is found to be 0.025 mol/L. What is the equilibrium cosntant for this reaction?

Do I just get the concentration of X2 and Y2 by dividing 0.5 mol with 1L and then take the answer and the equilibrium concentrations of XY - 0.025 mol/l and divide 0.025 by the concentration of X2 and Y2 in order to get the equilibrium constant?

Your explanation isn't clear to me but it sounds like you have it ok.

initial concentrations:

X2 = 0.5 M

Y2 = 0.5 M

XY = 0

change:

XY = +0.025

X2 = 0.025-(1mol X2/2 mol XY)=1/2*0.025

Y2 = 0.025-(1mol Y2/2 mol XY)=1/2*0.025

eqilibrium:

XY = 0.025

X2 = 0.5 - 1/2(0.025)

Y2 = 0.5 - 1/2(0.025)

Keq = (XY)^2/(X2)(Y2)=

(0.025)^2/(0.4875)^2 = ??

Check my thinking. Check my arithmetic.