Q8 of 36 Page 1

For a reaction


The proposed mechanism is as given below :


(1) H2O2 + I-→ H2O + IO- (slow)


(2) H2O2 + IO-→ H2O + I- + O2 (fast)


(i) Write rate law for the reaction.


(ii) Write the overall order of reaction.


(iii) Out of steps (1) and (2), which one is rate determining step?


(i) As we know, the rate of a complex reaction depends on the slowest step of the reaction mechanism. Therefore the rate law for the reaction will be as follows

Rate= k [H2O2][I-]


(ii) The overall order of the reaction is 1+1 =2


Explanation: Order of the reaction is the sum of powers of reactants in the rate law of any reaction.


(iii) Step 1 is the rate determining step as it is the slowest step and the overall rate of a reaction depends on the slowest step.


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Write IUPAC name of the complex [Cr(NH3)4Cl2]+. Draw structures of geometricalisomers for this complex.

Tetraaminedichlorochromium(iii)


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