Step 3. Substitute the equilibrium concentrations into the equilibrium constant expression and solve for x. (Note that y
Posted: Tue Jul 05, 2022 9:14 am
Step 3. Substitute the equilibrium concentrations into the equilibrium constant expression and solve for x. (Note that you must use the quadratic equation to solve this problem.) K = [FeSCN2+] [Fe³+ ][SCN-] = 0.0768 + x (0.0300-x) (0.0232-x) K 0 142x8.55x + 0.0220 = x = 0.00267 or 0.0575 (not a physically possible answer because it results in negative equilibrium concentrations for Fe³+ and SCN-) = Step 4. Use the value of a to calculate the new equilibrium concentrations. [Fe³+] = 0.0300 - x = 0.0273 M [SCN-] 0.0232x=0.0205 M [FeSCN²+] = 0.0768 + x = 0.0795 M Is your answer reasonable? As a final check of your answer, substitute the new equilibrium concentrations into the equilibrium constant expression and calculate K. H 142 0.0795 [FeSCN²+] [Fe³+][SCN-] (0.0273) (0.0205) <= 142