Acid–base reaction models as theories that complement each other. For example the current Lewis model has the broadest definition of what an acid and base are, with the Bronsted-Lowry theory being a subset of what acids and bases are, and the Arrhenius theory being the most restrictive. The first scientific concept of acids and bases was provided by Lavoisier in around 1776. Since Lavoisier's knowledge of strong acids was mainly restricted to oxoacids, such as (nitric acid) and (sulfuric acid), which tend to contain central atoms in high oxidation states surrounded by oxygen, and since he was not aware of the true
Chromotropic acid uses chromotropic acid. Chromotropic acid Chromotropic acid has the formula is (HO)CH(SOH). It can be used for as a reagent in the quantitative determination of the systemic herbicide, 2,4-dichlorophenoxyacetic acid. Chromotropic acid is also used for testing of presence of formaldehyde. The usefulness of this reagent in quantitative determination is the formation of a red colouration (peaking at 580 nm wavelength) when chromotropic acid in 50% sulfuric acid reacts with formaldehyde. The colouration is specific to this aldehyde and is not produced from other organic species such as ketones and carboxylic acids. The NIOSH Formaldehyde method #3500 is the reference