An acidic indicator ionises asI_(n) H hArr "In"^(-) + H^(+) . The molecular and ions of the indicator show different colours. The indicator changed it colour if its acidic of basic form completely predominant. Dissociation constant of an acidic indicator is 10^(-5) . At what p^(H) 80% of the indicator exists in molecular form ?

An acidic indicator ionises asI_(n) H hArr "In"^(-) + H^(+) . The mole

1.	An acidic indicator ionises asI_(n) H hArr "In"^(-) + H^(+) . The molecular and ions of the indicator show different colours. The indicator changed it colour if its acidic of basic form completely predominant. Dissociation constant of an acidic indicator is 10^(-5) . At what p^(H) 80% of the indicator exists in molecular form ?
Answer» `4.4` ` 6.6 ` ` 5.5` ` 3.3` SOLUTION :` pH = p^(kln )+ log ""([In^(-) ])/( [HIn]) ` ` pH =5+ log ""(20)/( 80 ) =5- log 4 = 4.4 `