Unit 6B
Timeline of tasks
Start date: After discussion with my tutor and laboratory technician, I set a suitable start date
for the practical part of the experiment, which was Friday the 24th May between 9.00am-
10.30am. This would give me sufficient time to gather and assemble all of the equipment
necessary and begin the experiment. I decided to then planned to continue the experiment on
the same day later on between 3-5pm, where I would be able to collate all of the evidence,
analyse and present the data found and if I found the experiment was taking too long in the first
period, I would be able to carry out the first step of the experiment (mixing the reactants, filtering
and washing off the solid product produced), and then carry out the second stage of the
experiment (recrystallization), or potentially repeat the experiment again if I felt that there was
any errors which occured in the first experiment conducted in the morning.
Milestones: Important milestones within my practical work include;
- Assembling and checking that all of the equipment necessary is functioning correctly,
without any malfunctions.
- Highlighting any areas of risk/health and safety aspects, and ensuring that necessary
safe precautions/protocols are put in place, such as personal protective equipment etc.
- Dissolving/ mixing the reactants together, filtering off the solid product (phenyl benzoate)
obtained, recrystallising the crude ester and potentially filtering with hot solution if the
solution produced as a result of recrystallization is not clear.
- Recording the results, analysing the data found and presenting it accordingly.
Completion: I have identified Tuesday 28th May as the final date to which I will draw the
physical aspects/ experimental processes to a close, and will give one week from that date to
finally complete a report with a full evaluation of my findings/results.
Method;
1. Dissolve 2.0 g of phenol in 30 cm3 of 2.0 M sodium hydroxide solution in a 250 cm3
conical flask.
2. Add 4.0 cm3 of benzoyl chloride, stopper the flask securely and shake vigorously for 15
minutes.
3. At the end of this time, a solid product should be obtained which can be filtered off with
suctional pump, breaking up any lumps on the filter paper with a spatula.
4. Wash thoroughly with water and drain.
5. Re-crystallise the crude ester from methylated spirits using a quantity of hot solvent
approximately 1.5 times the minimum required for complete solution. This is to ensure
that the phenol benzoate does not separate until the temperature of the solution has
fallen below the melting point of the ester.
6. Phenyl benzoate separates as colourless crystals. (If the solution is not clearly, filter the
hot solution, but you must consult with the teacher in advance.)
Resources;
Apparatus/materials/equipment: 2.0 grams of phenol, 30cm3 of 2.0M of sodium hydroxide
solution, 4.0cm3 of benzoyl chloride, methylated spirit (ethanol), 250cm3 conical flask, suctional
pump, filter paper, spatula, deionised water, sink and workstation.
Participants: Myself, a teacher/supervisor, laboratory technician.
Health and safety considerations;
The chemicals; phenol, sodium hydroxide and benzoyl chloride are potential hazards as they
can burn skin and eyes. For example, phenol is an organic chemical which is corrosive and
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