INTRODUCTION

Ideal stirrer tank reactor.

Continuous Stirrer-Tank Reactor (CSTR) usually runs at steady state with continuous

flow of reactants and products; the feed assumes a uniform composition throughout the reactor,

exit stream has the same composition as in the tank. There is an inlet stream(s) that bring all of

the reactants in at a particular rate. This stream(s) dumps into a large container; there is a shaft

with a blade attached (stirrer) in the reactor that rotates around to mix the reactants. Finally there

is an outlet stream, which the solution will exit from the reactor. The rates of the inlet and outlet

streams must be inside of the reactor is more accessible than many other reactors. Also because

of the simplicity of the components involved in the reactor, they are very easy to maintain and do

not require much work to keep running. It takes more space to mix the components in

comparison to other reactors.

There are many other types of reactors out there. For example, in a batch reactor there is

reactants put in a container and the container is closed for a period until the reaction is done. It is

used for small-scale operation, for testing new process that have not been fully developed, for

manufacture of expensive products, and for processes that are difficult to convert to continuous

operations. Besides that, it has the advantage of high conversions that can be obtained by leaving

the reactant for long periods of time. It also has the disadvantage which is it has a high costs per

batch and the difficulty of large-scale production.

Industrially it is used when relatively small amount of material are to be treated. In reactor design we have to know what size and type of reactor and method of operation that best for a given job. This may require the conditions in the reactor vary with position as well as time; this question can only be answered by a proper integration of the rate equation for the operation. This may pose difficulties because the temperature and composition of the reacting fluid may vary from point to point within the reactor, depending on the endothermic or exothermic character of the reaction, the rate of heat addition or removal from the system, and the flow pattern of fluid through the vessel. Briefly indicate the particular features and the main areas of application of these reactor types.

1

OBJECTIVES

The objectives of this are to determine the order of saponification reaction, to determine the

reaction rate constant, k and to determine the relationship between conversion, XA, reaction rate,

rA, reactor volume, V and feed rate, FAO. Besides, the other objectives are to determine the effect

of temperature on Reaction Rate Constant, k for batch reaction and to determine the activation

energy of saponification.

THEORY

IDEAL STIRRED-TANK REACTOR

A stirred-tank reactor (STR) may be operated either as a batch reactor or as a steady-state

flow reactor (better known as Continuous Stirred-Tank Reactor (CSTR)). The key or main

feature of this reactor is that mixing is complete so that properties such as temperature and

concentration of the reaction mixture are uniform in all parts of the vessel. Material balance of a

general chemical reaction is described below.

The conservation principle required that the mass of species A in an element of reactor volume

∆V obeys the following statement:

+ =

(1)

2

Rate of A into

volume element

Rate of A out of

volume element

Rate of A produced within volume element

Rate of A accumulated

within volume element

BATCH STIRRED-TANK REACTOR (BSTR)

In batch reactions, there are no feed or exit streams and therefore equation (1) can be simplified

into:

= (2)

The rate of reaction of component A is defined as:

-rA = 1/V (dNA/dt) by reaction = [moles of A which appear by reaction] (3)

[unit volume] [unit time]

By this definition, if A is a reaction product, the rate is positive; whereas if it is a reactant which

is consumed, the rate is negative.

Rearranging equation (3),

(-rA) V = NAO dXA (4)

dt

3

Rate of A produced

within volume element

Rate of A accumulated

within volume element

Integrating equation (4) gives,

t = NAO ∫ dXA__ (5)

(-rA)V

where t is the time required to achieve a conversion XA for either isothermal or non-isothermal

operation.

STEADY STATE MIXED FLOW REACTOR

The general material balance for this reactor is as equation (1) except no accumulation of the

material A in rector. As shown in figure 2 below, if FAO = vOCAO is the molar feed rate of the

component A to the reactor, then considering the reactor as a whole we have,

Input of A (moles/time) = FAO (1 – XAO) = FAO

Output of A (moles/time) = FA = FAO (1 – XAO)

Disappearance of A by reaction (moles/time) = (-rA) V

=

4

Figure 1: Graphical representation of the performance equations for batch reactor,

isothermal or non-isothermal at constant density.

Replacing equation (1) with mathematical formula above,

FAOXA = (-rA) V (6)

Which on arranging, will form the performance equation for mixed flow reactors,

or, (7)

In mixed flow reactors, XA = XAF and CA= CAF. In a constant density system,

XA = 1 – (CA/CAO)

5

Figure 2: Components of Mixed Flow Reactor

The performance equation can be rewritten in terms of concentration, or

(8)

These expressions relate the four terms XA, -rA, V, FAO; thus, knowing any three allows the fourth

to be found directly. In design, the size of reactor needed for a given duty or the extent of

conversion in a reactor of given size is found directly. Each steady-state point in a mixed flow

reactor gives the reaction rate for the conditions within the reactor. The mixed flow reactor

provides easier interpretation of reaction rate data and makes it very attractive in kinetic studies.

Graphical Representation of the Design Equations for Steady State Mixed Flow Reactor.

6

Figure 3: Plot of 1 / (-rA) versus XA

Or in constant systems

REACTION RATE IN MIXED REACTOR

Determination of Order of Reaction with Batch Reaction Data.

First Order Reaction (Unimolecular Type)

A Product

Suppose the reaction rate is the following type:

-ln = kt

7

Plot of –ln(CA/CAO) versus t will produce a straight line with a slope equals to rate constants, k.

-ln(CA/CAO)

Slope=k

Figure 5: Plot of –ln(CA/CAO) versus t

Irreversible Second-order Reaction (Bimolecular Type)

Consider the reaction:

A + B Products

The rate equation can be written as:

(11)

Plot of ln (CB/CA) versus t (time) will produce a straight line with slope equals (CBO – CAO)k.

8

Figure 6: Plot of ln(CB/CA) versus t

For second order reaction with equal initial concentrations of A and B, the rate equation can be

written based on only one component.

= = (12)

A plot of 1/CA versus t will produce a straight line with slope equals to k.

EFFECT OF TEMPERATURE ON RATE OF REACTION

As we increase the temperature the rate of reaction increases. This is because, if we heat a

substance, the particles move faster and so collide more frequently. That will speed up the rate of

reaction. Collisions between molecules will be more violent at higher temperatures. The higher

temperatures mean higher velocities. This means there will be less time between collisions. The

frequency of collisions will increase. The increased number of collisions and the greater violence

of collisions result in more effective collisions. The rate for the reaction increases. Reaction rates

are roughly doubled when the temperature increases by 10 degrees Kelvin.

9

In any single homogenous reaction, temperature, composition and reaction rate are

uniquely related. They can be represented graphically in one of three ways as shown in figure 8

below:

Figure 8: Plot of C versus T, r versus T, and r versus C.

PROCEDURES

Experiment A: Batch and Continuous Stirred Tank Reactor Experiments.

By studying the saponification reaction of ethyl acetate and sodium hydroxide to form sodium

acetate in a batch and in continuous stirred tank reactor, the students can evaluate the rate data

needed to design a production scale reactor.

A process flow diagram of the reactor is shown in Figure 9. This reactor has a total volume of

approximately 4 liters. A scale is provided to determine the reactor volume.

10

r2

r1

C2

C1

Reactants preparation procedure

1. 0.1 M NaOH and 0.1 M Ethyl acetate solutions are prepared in two separate 20 liter feed

tanks.

2. The concentration of 0.1 M NaOH solution is confirmed by titrating a small amount of it

with standard 0.1 M HCl using phenolphthalein as indicator. The concentration of ethyl

acetate solution, on the other hand, is evaluated in the following manner. First, 0.1 M

NaOH solution is added to a sample of feed solution such that the 0.1 M NaOH solution

is in excess to ensure all the ethyl acetate reacted. The mixture is reacted overnight. On

the following day, the amount of unreacted NaOH is determined by direct titration with

standard 0.1 M HCl. The ethyl acetate real concentration is recorded.

3. 1 liter of quenching solution of 0.25 M HCl and 1 liter of 0.1 M NaOH is prepared for

back titration.

Batch reaction procedure

1. Adjust the overflow tube in the reactor to begin a batch reactor to give a desired working

volume, say 2.5 liter. Pump P1 is switch on and starts pumping 1.25 liter of the 0.1 M

Ethyl acetate from the feed tank into the reactor. Then, pump P1 is switch off.

2. The stirrer is switch on and the speed in the mid range (say 180rpm) is set. Pump P2 is

switch on and start pumping 1.25 liter of the 0.1 M NaOH into the reactor. The pump is

stopped immediately the timing reaction is start. Record start time to.

3. Measured quickly 10 mL of the 0.25 M HCl in a flask.

4. Collect a 50 mL of a sample after 1 minute of reaction by opening the sampling valve and

added immediately 10 mL of 0.25 M HCl prepared in step 3, and mix. The HCl will

quench the reaction between ethyl acetate and sodium hydroxide.

5. The mixture is titrated with the 0.1 M NaOH to evaluate the amount of unreacted HCl.

6. Steps 3 to 5 are repeated for reaction times of 5, 10, 15, 20 and 25 minutes.

11

Experiment B: effect of temperature on reaction rate constant, k

The effect of temperature on reaction rate constant can be demonstrated by performing a batch

reaction run at different temperature.

1. Adjust the overflow tube in the reactor to begin a batch reactor to give a desired working

volume, say 2.5 liter. Pump P1 is switch on and starts pumping 1.25 liter of the 0.1 M

Ethyl acetate from the feed tank into the reactor. The stirrer is switch on and the speed in

the mid range is set. The heater is switch on. Run the cooling water.

2. Pump P2 is switch on and the valve is set for maximum flow rate and start pumping in

1.25 liters of the 0.1 M NaOH from the feed tank. The pump is stopped and immediately

starts timing the reaction and record start time, t0.

3. Measured quickly 10 mL of the 0.25 M HCl in a flask.

4. A 50 mL of the sample is collected after 1 minute of reaction time by opening the

sampling valve and immediately add to the 10 mL of 0.25 M HCl prepared in step 3, and

mix. The HCl will quench the reaction between ethyl acetate and sodium hydroxide.

5. The mixture is titrated with the 0.1 M NaOH to evaluate the amount of unreacted HCl.

6. Steps 4 to 6 are repeated fro reaction times of 5, 10, 15, 20 and 25 min.

7. Steps 1 to 7 are repeated for reaction temperatures of 45 and 65°C.

8. Plot C vs. T; r vs. T; r vs. C as in Figure 8.

9. Switch off all switches when you are finished with the experiment.

12

APPARATUS

Continuous stirred tank reactor ( Model BP:100)

Beaker

Burette

Solution: 0.1 NaOH, 0.1 Ethyl acetate, 0.25 HCl, and sodium hydroxide.

Spatula

Volumetric cylinder

13

RESULTS

Experiment A:

Reactants Quenching HCl Sample

CNaOH = 0.1 mole/liter (M)

CEA = 0.1 mole/liter (M)

CHCl = 0.25 mole/liter (M)

VHCl = 10 mL

Vs = 50 mL

Time(min)

(A)

Volume of Titrating NaOH(ml)

(B)

Volume of quenching HCl unreacted with NaOH in sample (ml)(C )

Volume of HCl reacted with NaOH in sample (ml)(D)

Mole of HCl reacted with NaOH in sample (mL)

(E)

Mole of NaOH unreacted in sample

(F)

Concentration of NaOH Unreacted with Ethyl Acetate (moles/liter) CA

(G)

Steady state fraction conversion of NaOH , XA

(H)

1 18.1 7.24 2.76 0.00069 0.00069 0.0138 0.862

10 20.2 8.08 1.92 0.00048 0.00048 0.0096 0.904

15 21.0 8.40 1.60 0.00040 0.00040 0.0080 0.920

20 21.2 8.48 1.52 0.00038 0.00038 0.0076 0.924

25 22.4 8.96 1.04 0.00026 0.00026 0.0052 0.948

14

Concentration of NaOH Reacted with Ethyl Acetate (moles/liter)(I)

Mole of NaOH Reacted with Ethyl Acetate in sample(J)

Concentration of Ethyl Acetate Reacted with NaOH(moles/liter)(K)

Concentration of Ethyl Acetate Unreacted(moles/liter)CB

(L)

0.0862 0.00431 0.0862 0.0138 72.464

0.0904 0.00452 0.0904 0.0096 104.17

0.0920 0.00460 0.0920 0.0080 125.00

0.0924 0.00462 0.0924 0.0076 131.58

0.0948 0.00474 0.0948 0.0052 192.31

15

Experiment B:

1. Temperature 45°C

Time(min)

(A)

Volume of Titrating NaOH(ml)

(B)

Volume of quenching HCl unreacted with NaOH in sample (ml)(C )

Volume of HCl reacted with NaOH in sample (ml)(D)

Mole of HCl reacted with NaOH in sample

(E)

Mole of NaOH unreacted in sample

(F)

Concentration of NaOH Unreacted with Ethyl Acetate (moles/liter) CA

(G)

Steady state fraction conversion of NaOH , XA

(H)

1 21.1 8.44 1.56 0.00039 0.00039 0.0078 0.922

5 22.5 9.00 1.00 0.00025 0.00025 0.0050 0.950

10 22.9 9.16 0.84 0.00021 0.00021 0.0042 0.958

15 22.3 8.92 1.08 0.00027 0.00027 0.0054 0.946

20 22.6 9.04 0.96 0.00024 0.00024 0.0048 0.952

25 23.7 9.48 0.52 0.00013 0.00013 0.0026 0.974

16

Concentration of NaOH Reacted with Ethyl Acetate (moles/liter)

(I)

Mole of NaOH Reacted with Ethyl Acetate in sample

(J)

Concentration of Ethyl Acetate Reacted with NaOH

(moles/liter)

(K)

Concentration of Ethyl Acetate Unreacted

(moles/liter)

CB

(L)

0.0922 0.00461 0.0922 0.0078 128.21

0.0950 0.00475 0.0950 0.0050 200.00

0.0958 0.00479 0.0958 0.0042 238.10

0.0946 0.00473 0.0946 0.0054 185.19

0.0952 0.00476 0.0952 0.0048 208.33

0.0974 0.00487 0.0974 0.0026 384.62

17

2. Temperature 65°C

Time(min)

(A)

Volume of Titrating NaOH(ml)

(B)

Volume of quenching HCl unreacted with NaOH in sample (ml)(C )

Volume of HCl reacted with NaOH in sample (ml)(D)

Mole of HCl reacted with NaOH in sample

(E)

Mole of NaOH unreacted in sample

(F)

Concentration of NaOH Unreacted with Ethyl Acetate (moles/liter) CA

(G)

Steady state fraction conversion of NaOH , XA

(H)

1 24.4 9.76 0.24 0.00006 0.00006 0.0012 0.988

5 23.3 9.32 0.68 0.00017 0.00017 0.0034 0.966

10 23.6 9.44 0.56 0.00014 0.00014 0.0028 0.972

15 24.1 9.64 0.36 0.00009 0.00009 0.0018 0.982

20 23.7 9.48 0.52 0.00013 0.00013 0.0026 0.974

25 23.3 9.32 0.68 0.00017 0.00017 0.0034 0.966

18

Concentration of NaOH Reacted with Ethyl Acetate (moles/liter)

(I)

Mole of NaOH Reacted with Ethyl Acetate in sample

(J)

Concentration of Ethyl Acetate Reacted with NaOH

(moles/liter)

(K)

Concentration of Ethyl Acetate Unreacted

(moles/liter)

CB

(L)

0.0988 0.00494 0.0988 0.0012 833.33

0.0966 0.00483 0.0966 0.0034 294.12

0.0972 0.00486 0.0972 0.0028 357.14

0.0982 0.00491 0.0982 0.0018 555.56

0.0974 0.0026 0.0974 0.0026 384.62

0.0966 0.0034 0.0966 0.0034 294.12

19

SAMPLE OF CALCULATION

Reactants

I. Concentration of NaOH ,CNaOH = 0.1 moles/liter

II. Concentration of Ethyl Acetate ,CEA = 0.1 moles/liter

Quenching HCl

I. Concentration of HCl ,C HCL = 0.25 moles/liter

II. Volume of HCl ,VHCl = 10 ml

Sample

I. Volume of sample,Vs = 50 ml

=0.05 L

Sample at room temperature 25°C

Sample of calculation for reaction after 5 minutes:

D = VHCl – (C)

= 10 ml – 7.24 ml

= 2.76ml

E = C HCl, STD x (D)

= (0.25)x (2.76x 10-3)

=0.00069 mole

20

F = E

= 0.00069 mole.

G ,CA = E/Vs

= 0.00069 /0.05

= 0.0138 moles/liters.

H, XA = 1-(CA/CA0)

= 1-(0.0138 /0.1)

= 0.862

I = CNaOH,A0 – (G)

=0.1 -0.0138

=0.0862 moles/litres

J = I x Vs

= 0.0862 x 0.05

=0.00431 mole

K = J/Vs

=0.00431 /0.05

=0.0862 moles/litres.

21

L,CB = CEA,O – (K)

= 0.1 – 0.0862

=0.0138 moles/litre

Calculation of time required for 95% conversion

The slope of graph is k.

By integration:

To find the time required for 95% conversion, slope from graph is obtained

At temperature 25°C

From the graph;

m = 4.510

Therefore the slope is k:

k = 4.510

When substitute the value of k = 4.7392,CA0 = 0.1 and X = 0.95 in equation above.

So we get,

-rA = (1/ 0.1)*( 0.95/(1-0.95)) = 4.510*t

t = 42.1286 minutes

22

At temperature 45°C

From the graph;

m = 7.353

Therefore the slope is k:

k = 7.353

When substitute the value of k = 7.353,CA0 = 0.1 and X= 0.95 in equation above.

So we get,

-rA = (1/ 0.1)*( 0.95/(1-0.95)) = 7.353*t

t = 25.8398 minutes

At temperature 65°C

From the graph;

m = 12.54

Therefore the slope is k

k = 12.54

When substitute the value of k = ,CA0 = 0.1 and X = 0.95 in equation above.

So we get,

-rA = (1/ 0.1)*( 0.95/(1-0.95)) = 12.54* t

t = 15.15 minutes

23

Temperature ( C)

Temperature (Kelvin) 1/T k ln k

25 298.15 0.00335 4.510 1.5063

45 318.15 0.00314 7.353 1.9951

65 338.15 0.00296 12.54 2.5289

Knowing that, slope = −E /R

Where, E is the activation energy

R is the gas law constant

Therefore, E = − (slope * R)

E = − (− 2613 X 8.314)

= 21.72 kJ / mole

24

At temperature 25°C

Time k CA CAO XA r

1 4.510 0.0138 0.1 0.862 8.59E-04

10 4.510 0.0096 0.1 0.904 4.16E-04

15 4.510 0.0080 0.1 0.920 2.89E-04

20 4.510 0.0076 0.1 0.924 2.60E-04

25 4.510 0.0052 0.1 0.948 1.22E-04

Example:

= 4.510(0.1)2(1-0.862)2

= 8.59E-04

At temperature 45°C

Time k CA CAO XA r

1 7.353 0.0078 0.1 0.922 4.47E-04

5 7.353 0.0050 0.1 0.950 1.84E-04

10 7.353 0.0042 0.1 0.958 1.30E-04

15 7.353 0.0054 0.1 0.946 2.14E-04

20 7.353 0.0048 0.1 0.952 1.69E-04

25 7.353 0.0026 0.1 0.974 4.97E-05

25

At temperature 65°C

Time k CA CAO XA r

1 12.54 0.0012 0.1 0.988 1.81E-05

5 12.54 0.0034 0.1 0.966 1.45E-04

10 12.54 0.0028 0.1 0.972 9.83E-05

15 12.54 0.0018 0.1 0.982 4.06E-05

20 12.54 0.0026 0.1 0.974 8.48E-05

25 12.54 0.0034 0.1 0.966 1.45E-04

Graph of C versus time

26

Graph of r versus time

Graph of r versus C

27

DISCUSSION

For this experiment, we are able to determine the order of saponification reaction, to

determine the reaction rate constant, k and to determine the relationship between conversion, XA,

reaction rate, rA, reactor volume, V and feed rate, FAO. Besides that, we need to find the effect of

temperature on Reaction Rate Constant, k for batch reaction and to determine the activation

energy of saponification.

Firstly, we conduct the experiment A which is for batch reaction process. Start the

experiment with a room temperature. Then, set up the apparatus and wait until 1 minute. After 1

minute, collect the sample (50 mL) and mix with the 10 mL of the 0.25 M HCl in the flask. Put

in a small amount of phenolphthalein in the flask in order to indicate the neutral level in the

mixture. Titrate the mixture with the 0.1 M NaOH until the mixture indicates the light pink. Note

the reading at the burette. The reading shows the amount of NaOH used in to neutralize the

mixture. Repeat the same step for reaction times of 5, 10, 15, 20 and 25 minutes. For this

experiment, the reaction at 5 minute is failed. It is because while pouring the sample in the flask

that containing 10 mL of the 0.25 M NaOH, the mixture turn to purple color. It means that the

flask is not washed properly. After that, we can determine the values of C,D,E,F,G,H,I,J,K, and

L.

In the theory, it states that when we get the same value of CA and CB, we have to

plot the graph of 1/CA versus time. From the graph, we can see that the straight line is produced.

So, it obeys the theory. We also find the slope of the graph which is indicates the value of

reaction rate constant, k = 4.510. This is the second order reaction, so, we can determine the

required time for the conversion of 95% by using the second order equation. So, the required

time is 42.1286 minutes. From the k values, we can determine the activation energy, E by

plotting the graph of ln k versus 1/T. So, E= 21.72 kJ / mole.

Secondly, we conduct the experiment B which is for batch reaction at different

temperatures. We need to find whether the reaction rate constants depend on the temperature or

not. So, we run the experiment at temperature 45°C and 65°C. As we know, at higher

temperature, the reaction rate is increase. When the reaction occurs at the high temperature, it

delivers more energy into the system and increase the reaction rate. During the reaction, more 28

collision between the molecules occurred. From the theory, it states that when the temperature

increases, the reaction rates also increase. When the reaction rate increases, the rate constant also

increase. So, the rate constant should increase but from the results, we get the negative value of k

for temperature 65°C. The value of k for 45°C is 7.353. So, from this case, it could be an error

during conduct this experiment. We also can find the required time for conversion 95%. So, it

shows that from temperature 25°C to 45°C, the required time are decreased. So, it means that

reaction occur more fast at the high temperature. The required time for temperature 65°C cannot

be considered because it shows the negative value. Then, we calculate the reaction rate for all

temperature. After that, plot the graph of C versus T, r versus T and r versus C.

From the graph, it can be seen that the graph of C versus T is quite same as shown

in the theory. So, it obeys the theory. From the graph, we can say that when the time increase, the

concentration increase and decrease. For the graph of r versus t, it is so difficult to describe.

From the theory, reaction rate should increase when the times increase. But from the results, it

not obeys the theory. Sometime it increase and sometimes it decrease. From the last graph which

is reaction rate versus concentration, the rate if reaction should increase directly proportional to

the concentration. But from our graph, it is so difficult to analyze. There are many error occurred

during the experiment.

29

CONCLUSION

As a conclusion, we can say that we are able to determine the order of

saponification reaction, to determine the reaction rate constant, k and to determine the

relationship between conversion, XA, reaction rate, rA, reactor volume, V and feed rate, FAO.

Besides that, we are able to determine the effect of temperature on Reaction Rate Constant, k for

batch reaction and to determine the activation energy of saponification.

From the results, we find that the value of CA and CB are the same. So, the order of

this reaction is a second order. Then, we have to plot the graph of 1/CA versus time. The graph

should be a straight line. The slope of the graph indicates the value of k. The reaction at the room

temperature give the value of k = 4.510. Then, the time required for conversion 95% is

calculated which is t= 42.1286 minutes. From the k values, we can determine the activation

energy, E by plotting the graph of ln k versus 1/T. So, E= 21.72 kJ / mole. Then, we need to

determine the effect of temperature on reaction rate constants, k. We run the experiment for 45°C

and 65°C. For 45°C, the value of k is 7.353 but for 65°C, the value of k is negative value. So, the

experiment for this temperature is failed. The value of k should increase when increasing the

temperature. Then, we need to plot the graph of C versus time, r versus time and r versus C. The

graph of C versus T is quite same as shown in the theory. So, it obeys the theory. From the

theory, we can say that when the time increase, the concentration increase and decrease. For the

graph of r versus t, it is so difficult to describe. From the theory, reaction rate should increase

when the times increase. But from the results, it not obeys the theory. Sometime it increase and

sometimes it decrease. From the last graph which is reaction rate versus concentration, the rate if

reaction should increase directly proportional to the concentration.

30

RECOMMENDATION

There are few recommendation for this experiment. Before start the experiment, make sure that

students read a lab manual and understand how to do. First, make sure all the apparatus are

washed before used. Then, during titration, control the valve of burette to make sure that we get

the light pink in the mixture. Besides that, read the reading at the burette carefully and avoid

parallax error. After that, we need to dispose all the liquids immediately after the experiment.

REFERENCES

Laboratory manual, Chemical Engineering Laboratory III, (CHE574 ), faculty Of

Chemical Engineering, Uitm.

www.cheathouse.com

www.wikipidea.org

Yahoo search engine (keyword: continuous stirrer tank reactor )

31

APPENDICES

32