ap chemistry
posted by amanda on .
a 0.76 mol sample of pcl5 is placed in a 500 ml reaction vessel. what is the concentration of pcl5 when the reaction
pcl5(g) ⇀↽ pcl3(g) + cl2(g)
has reached equilibrium at 250◦c (when kc = 1.8)

kc= [x)(x)/(2*.76x)= 1.8
x^2=1.8(1.52x)
solve that quadratic for x
x^2+1.8x2.74=0
x= (1.8+sqrt(3.24+10.96) )/2
x= .9+ 3.77/2= ..985 moles/liter
or conce of Pcl5 is 2*.76.985
check my math.