1.0 PROCEDURE

1.1 General Start Up Procedure

1. The following solutions are prepared :

a. 20L of Sodium Hydroxide, NaOH (0.1M)

b. 20L of Ethyl Acetate, Et (Ac) (0.1M)

c. 1L of Hydrochloric Acid, HCl (0.25M) for quenching

2. All valves are initially ensured closed.

3. The feed tanks are changed as follows :

a. The charge port caps for tank T1 and T2 are opened.

b. NaOH solution is carefully poured into vessel T2 and Et(Ac) solution is poured

into vessel T1.

c. The charge port caps for both tanks are closed.

4. The power for the control panel is turned on.

5. The heater is not switched on unless it is fully submerged in the liquid. The liquid

level is always maintained above the height of the heater to avoid damage to the

heater.

6. The stirrer assembly is made sure secured properly to avoid damage to the mechanical

seal.

7. All tubings are inspected periodically for leakage and worn out. Leakage might cause

damage to the equipments by corrosive reactants.

8. The unit is then ready for experiment.

1.2 Experimental Procedure

1. The general start up procedures are set up.

2. The overflow tube is adjusted to give a working volume of 2.5L.

3. Pump P1 is switched on and 1.25L of Ethyl Acetate is pumped from the feed pump

into the reactor. Then pump P2 is switched on and 1.25L of 0.1 NaOH into the reactor.

When the reactants volume reached 2.5L, pump P2 is switched off and the timer is

started immediately.

4. At the same time, 10ml of 0.25M HCl is prepared into a flask to quench with the

sample.

5. The sample is titrated with 0.1M Sodium Hydroxide, NaOH in the hood chamber to

determine the amount of unreacted HCl in the sample. 3 drops of phenolphthalein is

added to see the changes of solution colour.

6. Step 4 and 5 is repeated for reaction times 1,5,10,15,20 and 25 minutes.

7. All swith are switched of after the experiment done.

1.3 General Shut Down Procedure

1. Both pumps P1 and P2 are switched off. Stirrer also switched off.

2. The power for the control panel is turned off.

3. All apparatus and reactor are made sure cleaned properly after the experiment.

RECOMMENDATION

Throughout the experiment, in order to reduce the potential of inaccuracy in obtaining

measured data, a few recommendations and precautions must be considered during

performing the experiment.

First of all, for each experiment we must do the start up and start down procedure in

order to make sure there is no left over in the chamber and no leakage at the equipment.

Next, during the experiment, the titration should be repeated at least two times to get

accurate values and then take the average to make comparisons. This can minimize the error.

Thirdly, to improve the reading and get the better results, the positions of the eyes

must be parallel to the meniscus. Next, we should rinse all the apparatus before we use it and

again we must rinse the apparatus for the next solution. This is to ensure that all the beakers,

or burette is clean so that any chemical that we put into these apparatus does not react with

with the left over chemicals and hence do not disturb the reading.

Fourth, the titration should carefully conducted. Add the NaOH drop by drop using the

burette slowly. Titration should be immediately stopped when the indicator turned pink. This

to because a lot of error comes from titration. For a safety, do the titration only in the fume

chamber while wearing gloves. This is to ensure students’ safety.

Fifth, we should divide into two groups which is the first team in charge of the CSTR

machine while another group run the back titration procedures after the sample collected.

Last but not least, the stopper must immediately start up when the reactants volume

reach accurately 2.5L.

REFERENCES

APPENDIX