Question #c450e Chemistry Chemical Equilibrium Equilibrium Constants 1 Answer Ernest Z. Sep 25, 2014 The equilibrium constant is 3×102. Explanation: First, write the balanced chemical equation with an ICE table. mmmmmmmmmmFe3+m+mSCN-m⇌mFeSCN2+ I/mol⋅L-1:mmm1.0×10-3mm8.0×10-4mmmm0 C/mol⋅L-1:mmmml-xmmmmmll-xmmmmmll+x E/mol⋅L-1:l1.0×10-3−xm8.0×10-4−xmmmx At equilibrium, [FeSCN2+]=1.7×10-4lmol/L=xlmol/L So x=1.7×10-4 Then [Fe3+]=(1.0×10-3−x)lmol/L=(1.0×10-3–1.7×10-4)lmol/L =8.3×10-4lmol/L (1 significant figure + 1 guard digit) and [SCN-]=(8.0×10-4−x)lmol/L=(8.0×10-4−1.7×10-4)lmol/L =6.3×10-4lmol/L Kc=[FeSCN2+][Fe3+][SCN-]=1.7×10-48.3×10−4 ×6.3×10−4=3×102 Note: The answer can have only 1 significant figure, because the initial concentration of Fe3+ has only one digit after the decimal point. If you need more precision, you will have to recalculate. Answer link Related questions How does the equilibrium constant change with temperature? How do you find equilibrium constant for a reversable reaction? Question #a90d2 What is the equilibrium constant for the reaction of NH3 with water? What is the equation for finding the equilibrium constant for a chemical reaction? What is the equilibrium constant for the weak acid KHP? Consider this equilibrium: I2(s) + H2O(l) ⇌ H+(aq) + I-(aq) + HOI(aq). What is the Keq... What is the equilibrium constant for water? What is the equilibrium constant of citric acid? What is the rate of production of reactants compared with the rate of production of products at... See all questions in Equilibrium Constants Impact of this question 22825 views around the world You can reuse this answer Creative Commons License
