For the Hydrolysis of Methyl Acetate in Aqueous Solution, the Following Results Were Obtained - Chemistry


For the hydrolysis of methyl acetate in aqueous solution, the following results were obtained :

t/s 0 30 60
[CH3COOCH3] / mol L–1 0.60 0.30 0.15

(i) Show that it follows pseudo first order reaction, as the concentration of water remains constant.

(ii) Calculate the average rate of reaction between the time interval 30 to 60 seconds.

(Given log 2 = 0.3010, log 4 = 0.6021)



(i) For the hydrolysis of methyl acetate to be a pseudo first-order reaction, the reaction should be first order with respect to ester when [H2O] is constant. The rate constant k for a first order reaction is given by


where[R]Initial concentration of reactant

[RFinal concentration of reactant

At t30 s,


At t2 = 60 s,


It can be seen that the rate constant k for the reaction has a constant value under any given time interval. Hence, the given reaction follows the pseudo first-order kinetics.


(ii) Average rate of reaction between the time interval of 30–60 seconds is given by





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2014-2015 (March) Delhi Set 1

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Define "zero order reaction".

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(ii) How is the rate affected on increasing the concentration of A three times?

(iii) How is the rate affected when the concentrations of both A and B are doubled?


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(ii) Write the unit of k.

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Time / sec               Totalpressure / atm

0                              0.30

300                          0.50

Calculate the rate constant

(Given: log 2 = 0.301, log3 = 0.4771, log 4 = 0.6021)

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Rate = k [A] [B]2

How is the rate of reaction affected if the concentration of B is doubled?

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Rate = k [A] [B]2

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(i) Write the order and molecularity of this reaction.

(ii) Write the unit of k.

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(ii) What is the slope of the curve ?

(iii) Write the unit of rate constant for this reaction.

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SO2Cl2 (g) → SO2 (g) + Cl2 (g)

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1 0 0.4
2 100 0.7

Calculate the rate constant.

(Given : log 4 = 0.6021, log 2 = 0.3010)

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2A + B → C + D

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I 0.1 0.1 6.0 × 10−3
II 0.3 0.2 7.2 × 10−2
III 0.3 0.4 2.40 × 10−2
IV 0.4 0.1  

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  [NO] [H2] Rate
  Mol L-1 Mol L-1 Mol L-1 s-1
(1) 8 × 10-5 8 × 10-5 7 × 10-9
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(3) 24 × 10-5 32 × 10-5 8.4 × 10-8

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