FLOWER EXTRACT TAPAK DARA (CATHARANTHUS ROSEUS L) AS ACID-BASE INDICATOR Sitti Rahmawati, Vivi Dia Sangkota, Sitti Aminah, Siti Nuryanti, Hapsarina
Universitas Tadulako
Abstract
FLOWER EXTRACT TAPAK DARA (CATHARANTHUS ROSEUS L) AS ACID-BASE INDICATOR
Sitti Rahmawati1, Vivi Dia Sangkota1, Sitti Aminah1, Siti Nuryanti1, Hapsarina1
1 Mathematics and Sciences Educational, Faculty of Teacher Training and Educational Sciences, Universitas Tadulako, Jl. Soekarno Hatta Km 9 Tondo Palu 94118, Indonesia
Abstract
The aim of this research is to extract the tapak dara flower and prove it as an acid-base indicator. The tapak dara flower was washed with distilled water until clean, then ethyl acetate solvent was added and macerated. Subsequently filtered, then the filtered residue was extracted again with absolute methanol solvent. The extraction results were filtered using a gauze filter, then filtered again with filter paper. The filtered filtrate is ready to be used as an acid-base indicator. Then evaluated with a comparison indicator phenolphthalein and methyl orange for acid-base titration, namely a strong base with a strong acid, a weak base with a strong acid and a strong base with a weak acid. From the results of the study, it is known that the indicator of the extract of the tapak dara flower to show the equivalence point in the titration gives results that are equivalent to the comparison indicators. The results showed that indicators from tapak dara flower extract could be used instead of the synthetic indicators (phenolphthalein and methyl orange) that had been used so far.
Keywords: Flower tapak dara (Catharanthus roseus L), Acid-base indicator
