Question

The following reaction was studied experimentally at 25 °C. S2O82(aq) + 21'(ag) = 12(aq) + 2SO4 (aq) The reaction was found to be first order with respect to I and first order with respect to S208". A reaction was performed with [1] = 0.080 M and [S208²-] = 0.040 M. The initial rate of formation of 12 was found to be 1.25 x 10-M St. Provide an expression for the rate law for this reaction and determine the initial rate of formation of 12 when [1 ]o = 0.080 M & [S208 ]o = 0.060 M. a) Indicate whether the following statement is true or false and explain your reasoning: → Products, the rate of reaction remains constant as the reaction "For the first order reaction, A proceeds." b) If the above statement not describe a first order process, what order process does it describe?

Answer 1

5,08² (aq) + 2 I - (aq) 250q 2- (aq) + L2 (aq) The rate of the reaction for this Todine-clock reaction is given by - = K[S₂08 2- ] [ 1 ] where men are. the order with respect to 4082- and I = K[S208² - ] [ 1 ] respectively. Here man-1 (Giren] Given, 802-7=0.040M Karate constant [I] = 0.080 M = 125x10-6 M.S' 1.25x10-6 - K 0.040]*(0.080) or k = 1.25x10-6 0.040x0.080 ok - 0.00039 Again, I I ) - 0.080M. [52082-7. = 0.060M i The rate law for the reaction is then- z = 0.00039*60.060)% (0.080 = 1.875 x 10-6 M.st Νου, a) for the first order reaction, At Products, the rate of reaction remains constant as the reaction proceeds."

. Conen for a first order reaction, A products time The rate of reach is - = K[A] - - dla The above expression can be rearranged as - A - ho A = Ao e-kt af, ty & rate constant is increases with freeasing T. with increase of time are with the progress of the reaction the concentration of the reacthent, [A] decreases, there fore the value of s will be decreased. So, the rate of reaction will not be constant Hence the given statement is not truce. first for 6 The above statement not describe a order process. This statement is valid only the Zero order kinetics. so, the statement describes the Zero -order kinetic reaction.
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