Batch Reactor

Saponification Reaction Kinetics in a Batch Reactor ( Aim: To determine reaction rate constant and order of reaction of ethyl acetate with sodium hydroxide in an isothermal batch reactor at Room Temperature. Apparatus: Batch Reactor, Stirrer, Beaker, Conical Flask, Burette, Pipette etc. Chemicals: 0.1 N NaOH, 0.1 M Ethyl Acetate, 0.1 N HCl, Phenolphthalein indicator, 0.05 N NaOH(Titration), 0.1 N Oxalic Acid( for standardization purpose) Theory: A Batch Reactor is a closed system with no input and output streams. The reactor is charged with reactants, reaction is carried out and product is removed after completion of reaction. A batch reactor can operate under conditions like isothermal, perfectly mixed & constant volume. In a homogeneous reaction, all the reactants remain in single phase. The rate of reaction can be expressed as moles of reactant disappeared or product formed per unit volume of reaction mixture per unit time. Here the batch reactor is charged with reactants NaOH and Ethyl Acetate, in which the following reaction takes place, ( ( ( (D) & for the condition

, the reaction is assumed to be second order, and can be

represented as, & the corresponding rate equation becomes,

On integration gives, [

]

Procedure: Kinetics of Saponification reaction in a batch reactor: 1. Transfer 150 ml of 0.1 M NaOH solution maintain at room temperature in a batch reactor (stoppered bottle). 2. Add 150 ml of 0.1 M ethyl acetate solutions maintained at room temperature quickly in the batch reactor (stoppered bottle) to start the reaction, and immediately mix the content and start the stop watch. 3. At regular time interval, withdraw 10 ml of reaction mixture and put it in the marked conical flasks containing 15 ml of 0.1 N HCl and add 2-3 drops of phenolphthalein indicator. 4. Perform the titration with 0.05 N NaOH solutions in burette, till the solution becomes colourless to pink. 5. Note down the burette readings, and calculate the concentration of reactant time.

w.r.t.

Observations: 1) Reaction Temperature = 2) Standard Normality of NaOH for reaction = 3) Standard Normality of NaOH for titration = 4) Standard Normality of HCl (15ml) for quenching = Calculations of rate constant:

Unreacted i.e. Normality of NaOH Unreacted(

present in the reaction mixture.

[

]

Observation and Calculation Table Time ‘t’ min

Sr. No.

Temperature = (

BR (ml)

[

Graphs: i)

Plot the graph of [

]

Result: The value of rate constant ‘k’ for the given system i) By analytical method k = ii) By graphical method k =

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