Initial concentration of Reactants [itex]Fe^{3+}= 0.00027 M, (SCN)^{-}=0.00085 M[/itex]. Initial concentration of product [itex]Fe(SCN)^{2+}=0[/itex]. At the equilibrium, concentration of [itex] Fe(SCN)^{2+}=0.00018=2x[/itex]

[tex]K_c=\frac{0.00018}{(0.00027-x)*(0.00085-x)}=\frac{2x}{(0.00027-x)*(0.00085-x)}\Rightarrow 2x=0.00018,x=0.00009, K_c=\frac{0.00018}{(0.00018)*(0.00076)}=1315.789 liters/mol[/tex]