Extended Essays 2021

Limitation: The oil from the aqueous layer relies heavily on the technique when using the

separatory funnel. Throughout the experiment, traces of oil could be visually observed within the

aqueous layer, affecting the yield. Improvement: A centrifuge could have been used to separate

the oil from the aqueous layer, increasing the accuracy of the mass of oil produced by the

synthesis.

Systematic Errors Limitation: For the creation of the calibration curve, the 10 3 measuring cylinders were used to measure the required volumes of methyl salicylate (pure) and ethanol to make up the 10-50% concentrations. However, as the measuring cylinders have the uncertainty of ±0.2 3 , this

directly affects the concentration of methyl salicylate and hence the calibration curve used

throughout the investigation. Through combining the uncertainty for the volume of ethanol and

methyl salicylate for each percentage concentration, it was found that this uncertainty accounted

for 1-2% of error ( Appendix #15 ) Improvement: Larger volumes of the methyl salicylate and

ethanol (keeping the ratios) could have been used to reduce the effect of error on the overall

volume and hence concentration.

Extensions

For further exploration, I could determine the concentration of methyl salicylate in ointments

such as tiger balm though the same ferric chloride calibration curve method and then compare

the value to the concentrations of the synthesised methyl salicylate. This will allow for a more

accurate comparison of this investigation to the real industrial process.

Reliability of Sources

The sources used in this investigation originate from scientific journals, published textbooks and

the internet. A clear limitation in reliability of online sources is that independently published

online references can contain information which is not academically proven. However, as all my

online sources, such as PubChem & Lab Monk, have been either written or verified by qualified

experts, accredited (Ph.D.) authors or credited tutoring platforms, it can be said that the references

are valuable.

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