Ch.14 Acids and Bases
Arrhenius base
a substance that undergoes DISSOCIATION in water to give hydroxide ions OH⁻
Arrhenius acid
a substance that undergoes IONIZATION in water to give hydrogen ions H⁺ EXAMPLES (a) hydrochloric acid is a strong acid because it ionizes extensively (b) acetic acid is a weak acid because it does NOT ionize extensively
proton acceptor
a synonym for hydrogen ion acceptor
proton donor
a synonym for hydrogen ion donor
strong electrolyte
an aqueous solution that is a good conductor of electricity
weak electrolyte
an aqueous solution that is a poor conductor of electricity
properties of a BASE
(a) a base is a substance that releases hydroxide ions, OH⁻, into water (b) bitter taste (milk of magnesia is a base) (c) feel slippery, soapy (d) red litmus paper turns BLUE in the presence of hydroxide ions, OH⁻ (e) pH value is greater than 7 (f) neutralizes/reacts with acids to give SALT and WATER
properties of an ACID
(a) an acid is any substance that releases hydrogen ions, H⁺, into water (b) sour taste (lemons, limes, and vinegar are acidic) (c) blue litmus paper turns RED in the presence of hydrogen ions; blue litmus paper is used to test for acids (d) pH value less than 7 (e) neutralizes/reacts with bases to give SALT and WATER
net ionic equation
a chemical equation that represents an ionic reaction after spectator ions have been canceled
total ionic equation
a chemical equation that represents highly ionized substances in the ionic form and slightly ionized substances in the nonionized form
acid-base indicator
a chemical substance that changes color according to the pH of the solution
ionization constant of water
a constant that equals the product of the molar hydrogen ion concentration and the molar hydroxide ion concentration Kw = [H⁺] [OH⁻] = [1 * 10⁻⁷][1 * 10⁻⁷] = [1 * 10⁻¹⁴] in every aqueous solution, there is always a small number of both H⁺ and OH⁻
titration
a procedure for delivering a measured volume of solution through a buret
salt
a product obtained from a neutralization reaction in addition to water
buffer
a solution that resists changes in pH when an acid or a base is added
standard solution
a solution whose concentration has been established accurately (usually by titration to 3 or 4 significant digits)
amphiprotic
a substance capable of either accepting or donating a proton in an acid-base reaction
Brønsted-Lowry base
a substance that accepts a proton in an acid-base reaction
Brønsted-Lowry acid
a substance that donates a proton in an acid-base reaction
spectator ions
ions that are in an aqueous solution, but do not participate in a reaction and do not appear in the net ionic equation
hydronium ion
the ion that best represents the hydrogen ion in an aqueous solution
pH
the molar hydrogen ion concentration expressed on an exponential scale The pH of a solution expresses [H⁺] on an exponential scale. That is, a solution of pH 1 is 10 times more acidic than a solution of pH 2. To calculate the pH of a solution, we express [H⁺] as a power of 10 and change the sign of the exponent. For example, if [H⁺] is 10⁻² M, the pH is 2. Conversely, to find [H⁺] given the pH, we raise 10 to the negative pH. For example, if the pH is 3, [H⁺] is 10⁻³ M, that is, 0.001 M.
ionization
the process of a polar compound dissolving in water and forming positive and negative ions; for example, HCl dissolves in water to give hydrogen ions and chloride ions
dissociation
the process of an ionic compound dissolving in water and separating into positive and negative ions; for example, NaOH dissolves in water to give sodium ions and hydroxide ions
endpoint
the stage in a titration when the indicator changes color