Arrhenius Acids and Bases By Amhara Summerford-Ariail

Arrhenius Acids and Bases Theory Svente Arrenius (1859-1927) was an Swedish Chemist. Theorized that acids and bases must produce ions in solution Also theorized that aqueous solutions of acids and bases

Acids An Arrhenius acid is a chemical compound that increases the concentration of hydrogen ions, H+, in aqueous solution-all are electrolytes. Aqueous acids are the water solutions of of molecular compounds with ionizable hydrogen atoms. The hydrogen ion in aqueous solution is called H3O+, the hydronium ion. Ionization of an HNO3 molecule: HNO3(l) + H2O(l) -> H3O+(aq) + NO3-(aq)

Acid Strength Strong Acid: An scid that ionizes completely in aqueous solution, is also a strong electrolyte. Acid strength increases with increasing polarity and decreasing bond energy. Weak Acid: An acid that releases few hydrogen ions in aqueous solution. The aqueous solution of a weak acid has hydronium ions, anions, and dissolved acid molecules. Both the ionization of HCN and the reverse reaction occur at the same time: HCN(aq) + H2O(l) <-> H3O+(aq) + CN-(aq)

Bases An Arrenius base is a substance that increases the concentration of hydroxide ions, OH-, in aqueous solution. Most are ionic compounds containing metal cations and the hydroxide anion. Not all bases are ionic compounds. They dissociate when in water, when they are completely dissociated they make aqueous OH- ions, referred to as strongly basic. Bases that are not very soluble do not make a lot of hydroxide ions when added to water.

Base Strength Base strength: Depends on the extent the base dissociates, are strong electrolytes.

Questions What increases and decreases acid strength? What is the equation for the ionization of the HNO3 molecule? What are the definitions of an Arrenius base and acid?