Question

5. Consider the generic reaction shown below in which reactant A is converted to product B. A pure sample of reactant A is allowed to reach equilibrium. The concentrations of both A and B were monitored during this process and plotted below as a function of time. A(8)=B (8) concentration time a. Based on these data, is the value of Key for this reaction greater than or less than 1? Briefly explain how you can tell. b. The reaction is repeated using a pure sample of substance B as the starting material. Draw a graph like the one above showing how the concentrations of A and B will change during the course of this second reaction. C. Consider the rates of conversion of A™ Band B → Ain the reaction from part (b). Do these rates increase or decrease as the reaction approaches equilibrium? What happens to these rates once equilibrium is reached?

Answer 1

6 The for concentration us Time graph reaction Af Bris Secq (A) → CECB) Concentration time (a) k els concentration of B in Equilibrium neg = concentration of A in equilibrium n ie → Keg; = inex Ceq (B) Cea CA) But, Cegi (B) is less than Ceq (A). as given in data as shown in graph - [ Ceq (B) < Cq (A)} . keq <1 constant Equilibrium is one. less than (b) when, Pure Sample B is used then the reaction is as follow equilibrium) secona. B A(9) - Concentration on reaction & :. Now B. Bis Meactant end A A is product. They are . Equilibrium Scanned w CamScanner time

reaction As the reaction to progress is the Ceg, (B) [ equilibrium concentration af B). decreases and reaches constant value Again Ceg, (A) increases and reaches constant value at equilibrium. © . let the rate (R) on for forward A B be Re and Baandard B A be R.b. reaction a As the reaction approaches. equilibrium; Ree decreases as the [A] decreases and RF = K[AJ. . Concentration of a decreases as Meaction proceeds, so RF decreases because Rate a concentration af Meactant: Again Rate of back o increases. " Rate of back ward reaction Rb increases as [B] increases. Rb = K[B] .. Rb increases because [B] when equilibrium is reached. RF = Rb. Cie both the CamScaimate become e qaldi Scanned with