How does the pH of a solvent influence the solubility of turmeric in it?
DOI:
https://doi.org/10.47611/jsrhs.v10i2.1527Keywords:
Colorimetry, Turmeric, Solubility, Curcumin, High School, IB, pH, Beer-Lambert law, pH Indicators, Removing stainsAbstract
Turmeric is a culinary spice used in many meals particularly in traditional Indian cuisine. Turmeric has a bright orange colour that is due to the presence of curcumin within it. Because of it’s bright colour, it is important to be able to easily remove turmeric stains from clothing. In my research I attempted to find the ideal conditions for removing turmeric stains and found that no investigation had been made into the impact the pH of the cleaning agent on its effectiveness.
In this investigation the solubility of turmeric in 5 different solutions was found using colorimetry. Colorimetry is a scientific technique that is used to determine the concentration of coloured solutions by the application of the Beer-Lambert law. This method allowed the solubility of turmeric to be determined, in a range of different solvents with good accuracy and precision. The experimental results showed that turmeric was more soluble in solutions with higher pH levels as the solubility in 0.2M sodium hydroxide was 17.6mg/mL and in pure ethanol was 10.1mg/mL, while the solubility in hydrochloric acid was only 0.034mg/mL.
Ultimately, this investigation shows that turmeric is more soluble in basic solutions and hence basic solvents are more effective removers of turmeric stains. A claim which was shown to be true by washing turmeric stained clothes with the solvents and comparing the cleaned clothes. This investigation also shows that turmeric could be used as a pH indicator as it has a different colour in different pH solutions.
Downloads
References or Bibliography
• Brown, C. and Ford, M., 2014. Higher Level Chemistry. 2nd ed. Harlow: Pearson Education Limited.
• Jagannathan, R., Abraham, P. and Poddar, P., 2012. Temperature-Dependent Spectroscopic Evidences of Curcumin in Aqueous Medium: A Mechanistic Study of Its Solubility and Stability. The Journal of Physical Chemistry B, [online] 116(50), pp.14533-14540. Available at: https://pubs.acs.org/doi/10.1021/jp3050516 [Accessed 6 June 2020].
• Ncbi. 2010. Stabilization of Curcumin by Complexation with Divalent Cations in Glycerol/Water System. [ONLINE] Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904446/. [Accessed 1 June 2020].
• Ncbi. 2011. Turmeric, the Golden Spice. [ONLINE] Available at: https://www.ncbi.nlm.nih.gov/books/NBK92752/. [Accessed 21 June 2020].
• Priyadarsini, K., 2014. The Chemistry of Curcumin: From Extraction to Therapeutic Agent. Molecules, [Online]. 19, 0. Available at: https://www.researchgate.net/publication/269182694_The_Chemistry_of_Curcumin_From_Extraction_to_Therapeutic_Agent [Accessed 8 June 2020].
• Science.cleapss.org.uk. 2019. Ethanol. [online] Available at: http://science.cleapss.org.uk/Resource/SSS060-Ethanol.pdf [Accessed 18 June 2020].
• Science.cleapss.org.uk. 2019. Hydrochloric acid. [online] Available at: http://science.cleapss.org.uk/Resource/SSS020-Hydrochloric-acid.pdf [Accessed 18 June 2020].
• Science.cleapss.org.uk. 2019. Higher alcohols. [online] Available at: http://science.cleapss.org.uk/Resource/SSS066-Higher-alcohols-propanols-butanols-pentanols.pdf [Accessed 18 June 2020].
• Science.cleapss.org.uk. 2019. Sodium hydroxide. [online] Available at: http://science.cleapss.org.uk/Resource/SSS031-Sodium-hydroxide.pdf Accessed 18 June 2020].
• Science Direct. 2014. Colorimetry. [ONLINE] Available at: https://www.sciencedirect.com/topics/chemical-engineering/colorimetry#:~:text=Colorimetry%20is%20a%20scientific%20technique,is%20proportional%20to%20the%20absorbance. [Accessed 21 June 2020].
• Wikipedia. 2020. pH indicator. [ONLINE] Available at: https://en.wikipedia.org/wiki/PH_indicator . [Accessed 21 June 2020].
Published
How to Cite
Issue
Section
Copyright (c) 2021 Miyu Bansal; Uma Sivakumar
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Copyright holder(s) granted JSR a perpetual, non-exclusive license to distriute & display this article.
