Biochemistry Research International / 2015 / Article / Tab 8 / Research Article
Comparative Analysis of the Properties of Acid-Base Indicator of Rose (Rosa setigera ), Allamanda (Allamanda cathartica ), and Hibiscus (Hibiscus rosa-sinensis ) Flowers Table 8 Acid-base titration with extract as indicator.
Indicator Strong acid (H2 SO4 ) Weak acid (CH3 COOH) Strong base (NaOH) Strong base (NaOH) cm3 cm3 Phenolphthalein 12.04 ± 0.15 41.80 ± 0.30 Methyl red 12.04 ± 0.05 44.20 ± 0.15 Bromophenol blue 12.06 ± 0.10 60.50 ± 0.05 Hibiscus (cold extract) 11.70 ± 0.06 25.00 ± 0.15 Hibiscus (methanol extract) 11.50 ± 0.25 25.50 ± 0.60 Allamanda (cold extract) 12.60 ± 0.20 42.60 ± 0.35 Allamanda (methanol extract) 12.00 ± 0.15 36.00 ± 0.50 Rose (cold extract) 13.00 ± 0.60 20.50 ± 0.45 Rose (methanol extract) 13.01 ± 0.40 22.60 ± 0.25
Values are mean ± SD of 3 readings.