Chem 208 1st Edition Lecture 17Outline of Last Lecture I. Sample Problem 17.9II. Steps in solving equilibrium problemsOutline of Current Lecture I. Le Châtelier’s PrincipleII. The Effect of a Change in ConcentrationCurrent LectureI. Le Châtelier’s PrincipleA. When a chemical system at equilibrium is disturbed, it retainsequilibrium by undergoing a net reaction that reduces the effect of the disturbance.B. A system is disturbed when a change in conditions forces it temporarily out of equilibrium.C. The system responds to a disturbance by a shift in the equilibrium position.D. A shift to the left is a net reaction from product to reactant.E. A shift to the right is a net reaction from reactant to product.II. The Effect of a Change in ConcentrationA. If the concentration of A increases, the system reacts to consume some of it.B. If a reactant is added, the equilibrium position shifts to the right.C. If a product is added, the equilibrium position shifts to the left.D. If the concentration of B decreases, the system reacts to consume some of it.E. If a reactant is removed, the equilibrium position shifts to the left.F. If a product is removed, the equilibrium position shifts to the right.G. Only substances that appear in the expression for Q can have an effect.H. A change in concentration has noeffect on the value of K.I. PCl3(g) + Cl2(g) >> PCl5(g)J. When Cl2 (yellow curve) is added, itsconcentration increases instantly(vertical part of yellow curve) and thenfalls gradually as it reacts with PCl3 toThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.form more PCl5. Equilibrium is re-established at new concentrations but with the same value of
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