Chapter 17: Acids and Bases Flashcards
carboxylic acid
An organic acid containing the functional group – COOH. It is often found in substances derived from living organisms. Acetic acid is an example.
alkaloids
Organic bases found in plants that are often poisonous.
Acid
A substance that produces H+ ions in aqueous solution.
Base
A substance that produces OH- ions in aqueous solution.
Arrhenius definition
The definition of an acid as a substance that produces H+ions in aqueous solution ad a base as a substance that produces OH- ions in aqueous solution.
hydronium ion
H3O+ ion, the ion formed from the association of a water molecule with an H+ ion donated by an acid.
strong acid
Completely ionizes in solution. Represented by single arrow.
The concentration of H3O+ in a strong acid solution is equal to the concentration of the strong acid because we ignore the contribution of the autoionization of water.
weak acid
Partially ionizes. Represented with an equilibrium arrow (double).
The concentration of H3O+ is not equal to the concentration of the weak acid. It is less acidic because it only partially ionizes. Needs to be solved by equilibrium technique.
strong base
One that completely dissociates in solution.
weak base
Partially ionizes in water.
Bronsted-Lowry definition
The definitions of an acid as a proton (H+ ion) donor and a base as a proton acceptor.
ampohteric
Substances that can act as acids or bases. i.e. water.
conjugate acid-base pair
Two substances related to each other by the transfer of a proton.
i.e.: NH4+ & NH3
Conjugate acid
Any base to which a proton has been added.
conjugate base
Any acid from which a proton has been removed.
monoprotic acids
Acids containing only one ionizable proton.
Hydrochloric acid (HCl)
Nitric acid(HNO3)
Hydrobromic acid (HBr)
Hydrioidic acid (HI)
Perchloric acid (HClO4)
diprotic acid
An acid containing two ionizable protons.
Sulfuric acid (H2SO4)
Triprotic
Acids containing three ionizable protons.
Phosphoric acid (H3PO4)
Common Strong Acids
Hydrochloric acid (HCl)
Nitric acid(HNO3)
Hydrobromic acid (HBr)
Hydrioidic acid (HI)
Perchloric acid (HClO4)
Sulfuric acid (H2SO4)
Common weak acids
Hydrofluoric acid (HF)
Acetic acid (HC2H3O2)
Formic acid (HCHO2)
Sulfurous acid (H2SO3)
Carbonic acid (H2CO3)
Phosphoric acid (H3PO4)
Acid ionization constant (Ka)
Equilibrium constant for the ionization reaction of the weak acid. It is relatively small and the smaller the constant, the less the acid ionizes, and the weaker the acid.
Ka = [H3O+][A-]/[HA] = [H+][A-]/[HA]
Autoionization
The process when water acts as an acid and a base with itself.
H2O(l) + H2O(l) ⇔ H3O(aq) + OH-(aq)
H2O(l) ⇔ H+(aq) + OH-(aq)
ion product constant for water (Kw)
aka dissociation constant for water.
Kw = [H3O+][OH-] = [H+][OH-]
At 25ºC, Kw=1.0 x 10-14
In all aqueous solutions both H3O+ and OH- are present and Kw = 1E-14.
acidic solution
An acid that creates additional H3O+ ions, causing H3O+ to increase.
[H3O+] > [OH-] BUT it still equals 1.0E-14 Kw