Incorrect statement for the use of indicators in acid–base titration is : (1) Methyl orange may be used for a weak acid vs weak base titration. (2) Methyl orange is a suitable indicator for a strong acid vs weak base titration (3) Phenolphthalein is a suitable indicator for a weak acid vs strong base titration (4) Phenolphthalein may be used for a strong acid vs strong base titration.