Chapter 9 - Acids, Bases, and Buffers

Acids

proton donors

pH

hydrogen ion concentration

Hydronium ion (H3O+)

the positive ion formed when a water molecule gains a hydrogen ion

Bases

proton acceptors

Weak acids

acids that are weak electrolytes

Strong acids

acids that ionize completely

Weak bases

react with water to form the hydroxide ion and the conjugate acid of the base

Arrhenius bases

dissociate to produce an excess of hydroxide ions in solution

Strong bases

bases that dissociate completely in water

Neutralization

a reaction between an acid and a base that produces water and a salt

Antacids

neutralize the acids in the stomach

Chemical equilibrium

a state of balance in which the rate of a forward reaction equals the rate of the reverse reaction and the concentrations of products and reactants remain unchanged

Equilibrium constant (K)

value of the reaction quotient for a system at equilibrium

Balanced chemical equation

chemical equation with the same number of atoms of each element on both sides of the equation

Le Chatelier's Principle

when stress is applied to a system at equilibrium, the system changes to relieve the stress

Acid dissociation constant

the ratio of the concentration of the dissociated form of an acid to the concentration of the undissociated form

Conjugation acids & bases

differ by one (H+) or proton

Autoionization

the transfer of a proton from one molecule to another of the same substance

pH scale

measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14

Basic

pH greater than 7

Neutral

pH of 7

Acidic

pH less than 7

Henderson-Hasselbalch equation

pHm= pKa + log(c. base/acid)

Buffer

compound that prevents sharp, sudden changes in pH

Hypoventilates

shallow breathing, not enough CO2 is exhaled

Respiratory acidosis

a drop in blood pH due to hypoventilation (too little breathing) and a resulting accumulation of Co2.

Hyperventilates

exhaling excessively, exhaling too much CO2

Respiratory alkalosis

a rise in blood pH due to hyperventilation (excessive breathing) and a resulting decrease in CO2.

Metabolic acidosis

decreased pH in blood and body tissues as a result of an upset in metabolism

Metabolic alkalosis

elevation of HCO3- usually caused by an excessive loss of metabolic acids