Study of Acid-Base Indicator Property of the Selected Natural Food Colour Source Juice Beetroot (Beta Vulgaris), Tomato (Solanum Lycopersicon) And Carrot (Dacus Carota).

Artificial indicators are the choice of acid - base titrimetric analysis, but due to environmental pollution, availability, and ease of preparation and cost effectiveness, the search for natural compounds as acid- base indicator started. The beetroot, carrots and tomatoes, are one of these compounds...

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Bibliographic Details
Main Author: Akorabirungi, Hillary
Format: Thesis
Language:en_US
Published: Kabale University 2024
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Online Access:http://hdl.handle.net/20.500.12493/1677
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Summary:Artificial indicators are the choice of acid - base titrimetric analysis, but due to environmental pollution, availability, and ease of preparation and cost effectiveness, the search for natural compounds as acid- base indicator started. The beetroot, carrots and tomatoes, are one of these compounds being investigated in this study. In this research project, both quantitative and qualitative methods were employed to bring out unbiased results.In acid-base titrations, indicators are used to show a sharp color changes at interval of pH.. A study has been done to investigate the indicator activity of aqueous extract of beetroot , carrot and tomato pigments and compared with that of already existing synthetic indicators. Pigments were extracted using hot water and a definite volume was added which gave accurate and reliable results for all the different types of neutralization titrations - strong acid against strong base, weak acid against strong base. The work proved to be acceptable in introducing root pigments as a substitute to the synthetic acid-base indicators. BCT were cut into small pieces, grinded to remove the juice and boiled in 1000cm3 of distilled water, filtrated using a filter funnel to obtain the juice indicators. The respective juice indicators which were used as pH indicators in acid-base titration of0. lM HCl and 0. lM NaOH in the PH titration experiments. For every experiment, the solution of hydrochloric acid was filled in the burette, while 25.00cm3 of natural indicator was pipetted, put in the beaker with the PH meter for measuring the PH of the solution .Solution in the burette was titrated against the solution in the beaker. The PH of the solution in the beaker could be measured for every 0.5ml of the solution added from the burette to the solution in the beaker. In the pH titration of the plant extracts with 0.lMNaOH and 0.lMHCL, the beetroot juice extract exhibited 1.258925x10 and 1.0x10 for the Kb and Ka values, 0.000255 and 3.16227810° for the Carrot extract ,3.981072107 and 3.981072x10° for the Tomato extract. Solutions with low Ka and Kb values are weak acids and bases respectively. For the weak acid, the Ka ranges from 10? to 101.The three indicators can be used as substitutes for the artificial indicators since the Ka and Kb values have been determined of which can tell their PH working ranges.