Acids and bases

Acids and bases

1. Arrhenius

   • Theory
     • Acids are the substances which they produce the hydrogen ions in a solution.
       • Bases are substances in which they produce hydroxide ions in the solution.
   • An Arrhenius acid is a substance that when added to water increases the concentration of H1+ ions present. The chemical formulas of Arrhenius acids are written with the acidic hydrogens first. An Arrhenius base is a substance that when added to water increases the concentration of OH1- ions present. HCl is an example of an Arrhenius acid and NaOH is an example of an Arrhenius base.

2. Bronsted-Lowry

   • Theory
     • An acid is a proton (hydrogen ion) donor.
       • A base is a proton (hydrogen ion) acceptor.
   • Bronsted-Lowry acid is defined as anything that releases H1+ ions; a Bronsted-Lowry base is defined as anything that accepts H1+ ions. This definition includes all Arrhenius acids and bases but, as we will soon see, it is a bit more general

3. Lewis

   • Theory
     • A Lewis acid is an electron pair acceptor.
       • A Lewis base is an electron pair donor.
   • Lewis theory suggests that acids react with bases to share a pair of electrons, with no change in the oxidation numbers of any atoms. Many chemical reactions can be sorted into one or the other of these classes. Either electrons are transferred from one atom to another, or the atoms come together to share a pair of electrons.