MAKING OF ACID-BASE INDICATORS PAPER FROM FLOWER EXTRACTS

• Main Author: Alwi, Fahmiyah
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34624
• Institution: Institut Teknologi Bandung

Acid-base indicators are a substance that can have different color with changes in pH. Acid-base indicators can be either natural indicators or syinthetic indicators. Natural indicators can be obtained by extracting flower crown with alcohol while syinthetic indicators such as universal indicator are available commercially. Flower extract and universal indicator shows different color in different pH. To understand the changes at the color flower extract and universal indicator, in this study universal indicator was made from 5 combination of syinthetic indicator, namely thymol blue, methyl orange, mehyl red, brom tymol blue and fenolftalein while flower extracts were made from 8 types of flower namely Hibiscus rosa sinensis, Eritrina crystal gally, Catharanthus roseus, Rhododendron indicum, Sarca indica, Canna generalis, Pachitachis lutea and Ruellia malacosperma. Changes of color indicators are observed by using buffer solutions of pH 2,5 to 12. To be easier to practice at school, the indicators were absorbed on filter paper. Universal indicator paper shows different color in the range pH 2,5-3, 4-5, 6-7, 8-10 and 11-12 , while acid-base indicator paper made of flower extracts showed a different color on the pH < 3, pH 4-7 and pH > 8 . The color depends on the types of flowers .