Herrington found a substance that tastes sour, turns litmus paper red and has a pH of 1.4. Herrington found a(n)

Herrington found an ACID.

Explanation:

Acid is defined as a substance which when dissolved in water, produces hydroxonium ion as the only positive ion. It is a proton donor. Acid can be used for the production of fertilizers, dyes, detergents, drugs, plastic and explosives.

The characteristics of an acid includes:

--> They have sour taste

--> In pH scale, values below 7 indicates acidity increasing downwards from 6 to 1.

--> strong acids are corrosive.

--> substances called indicators give specific colours in acidic media. For example: blue litmus turns red; phenolphthalein turns colourless; and methyl orange turns pink.

--> they react with active metals, that is, those above hydrogen on the activity series, to liberate hydrogen gas.

--> they react with bases to produce salts and water as the only products. This reaction is known as neutralisation reaction.

The above characteristics about acid shows that the substance found by Herrington is an ACID.