THEORIES THAT DEFINE ACIDS AND BASES

THEORIES THAT DEFINE ACIDS AND BASES

Arrhenius theory

Bronsted-Lowry theory

Lewis theory

the acids are the hydrogen-containing compounds which give H+ ions or protons on dissociation in water and bases are the hydroxide compounds which give OH− ions on dissociation in water.

An acid is a chemical species capable of donating a proton or hydrogen cation. A base is a chemical species capable of accepting a proton.

acid is an electron-pair acceptor. A base is any substance.

definition

An Arrhenius base is any species that increases the concentration of OH−start text, O, H, end text, start superscript, minus, end superscript in aqueous solution.

To determine if its an acid or a base, count the hydrogens on each substance before and after the reaction. If the number of hydrogens has decreased that substance is the acid. If the number of hydrogens has increased that substance is the base

A Lewis base is therefore an electron-pair donor.

Lewis acid is an electron-pair acceptor.

characteristics

examples of Arrhenius acids include sulfuric acid (H2SO4), hydrobromic acid(HBr), and nitric acid (HNO3). Examples of Arrhenius bases include sodium hydroxide(NaOH) and potassium hydroxide (KOH).

Ammonia is the Bronsted-Lowry base because it is the 'proton acceptor' - it accepts a hydrogen atom from water. On the other hand, water is the Bronsted-Lowry acid because it is the 'proton donor'.

For example, NH3 is a Lewis base, because it can donate its lone pair of electrons.

examples