Acid and Base

353 Words2 Pages
Acids and Bases – Intro and Review Theories: Arrhenius Theory -first theory concerning acids and bases -all acids produce hydrogen ions (H+) in water e.g. -all bases produce hydroxide ions (OH-1)in water -acid-base neutralization is simply the combination of hydrogen ions with hydroxide ions to produce water e.g. Today we know that hydrogen ions only exist in water when they are attached to something else. When they attach themselves to water molecules they form hydronium ions (H3O+). Lewis diagram: Non-metal oxides -called acidic anhydrides (anhydride means “without water”) -these react with water to form molecular acids containing H+ E.g. SO3(g) + H2O(l) ( H2SO4(aq) Note: H2CO3 is too unstable to be isolated as a pure compound. CO is not an acidic anhydride. Bases: Two categories 1) Ionic compounds that contain hydroxide ions or O2- 2) Molecular compounds that react with water to give hydroxide ions Bronsted-Lowry Theory of Acids and Bases -acids are proton donors -bases are proton acceptors -acid-base reactions involve an proton transfer from acid to base -involves conjugate acid-base pairs e.g. NH3 and CH3COOH Note: Conjugate acid-base pairs differ by one proton and a charge of 1 Amphoteric/Amphiprotic -a substance capable of reacting as an acid or a base -water in the above examples is amphoteric -another example is HCO3-1 which is part of the buffer system in our blood Polyprotic Acids -acids that have more than one ionisable hydrogen e.g. H2SO4 is an example of a diprotic acid Strong and Weak Acids and Bases -strong acids and bases complete react with water to release all of their hydrogen or hydroxide ions -weak acids and bases only partially ionize/dissociate and thus form equilibrium systems and have equilibrium constants associated with them -since

More about Acid and Base

Open Document