Pemanfaatan Ekstrak Buah Senduduk (Melastoma malabathricum L.) sebagai Alternatif Indikator Alami Titrasi Asam Basa dan Implementasinya dalam Praktikum di Sekolah

Abstract

Abstract This research aimed to know which ones produce the solvent a clear color change, precision and accuracy of its use, and can be used as natural indicator a substitute for synthesis indicator. Extraction method used was maceration for 24 hours with solvent of aquadest and ethanol 96% plus 1% concentrated HCl. Determination of pH trajectory using the analysis of color change in the solution of buffer and change the wavelength by UV-Vis spectrophotometer. The feasibility of natural indicator as alternatively substitution of synthesis indicator was assessed through a questionnaire by high school teachers Pekanbaru. Results showed that the trajectory of pH indicator natural from 3.92 to 4.91, the resulting color change was very stark contrast, the pink-purple, precision level of 0.251 and accuracy of 2.58%. Percentage of questionnaires showed a very clear titration discoloration of 85.71%, discoloration of natural indicator titration than synthetic was very clear 85.71%, security of natural indicator for environments was very secure 71.43%, the ratio of security with synthesis indicator was very secure 85.71%, its use as a determinant endpoint can greatly 85.71% , its comparison with the synthesis of 71,43% clear in determining the endpoint. Keywords: Senduduk Fruit (Melastoma malabathricum L.), anthocyanin, maceration, indicators ,acid-basetitration.