Plant leaves as a pH indicator

ABSTRACT

Extract of leaves of Amrood [Psidium guajava], Eucalyptus which have same classifications and Anar [Punica granatum] with same order [Myrtales] but different family and Shisham [Dalbergia Sissoo Roxb. or Sisu] and Hibiscus with different order have been obtained and their behaviour observed in acid or basic medium as a function of colour change, i.e. acid-base indicator. The extract of these leaves, which are highly coloured, act, as pH indicator. The indicator constant [pK1n] for the extract of these leaves was found to be 7.3 pH range 6.3 to 8.3 and K1n was 5 x 10[-8]