Introduction to Acids and Bases



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Acid  -  A substance that has the potential to donate a proton (H+) or accept an electron pair.
Acidic  -  Having a pH less than 7.
Arrhenius Model  -  Arrhenius proposed that acids are substances that produce protons, H+, in aqueous solution, whereas bases produce hydroxide ions, OH-, in aqueous solution. Compare his model with the Bronsted-Lowry definition and the Lewis definition.
Base  -  A substance that can accept a proton, release OH-, or donate an electron pair.
Bronsted-Lowry Definition  -  Bronsted and Lowry define an acid as a proton (H+) donor and a base as a proton acceptor. Compare this model with the Arrhenius Model and the Lewis definition.
Buffer  -  A solution composed of an acid and its conjugate base that serves to moderate the pH of the solution.
Conjugate Acid  -  A molecule that can be described as a base that has gained one proton.
Conjugate Base  -  A molecule that can be described as an acid that has lost one proton.
Indicator  -  A molecule whose conjugate acid or conjugate base has a different color. Indicators are used to measure the pH of a solution.
Lewis Definition  -  Lewis defined an acid as an electron pair acceptor and a base as an electron pair donor. Compare his model with the Arrhenius model and the Bronsted-Lowry definition.
pH  -  A measure of the hydrogen ion concentration, it is equal to - log [H+], where [H+] is the concentration of protons.
Redox  -  Short for "reduction-oxidation," a reaction that involves paired oxidation and reduction processes described in the Electrochemistry SparkNote.
Titration  -  An experiment that neutralizes an unknown amount of acid or base with a known volume and concentration of acid or base to determine the amount of unknown acid or base.