acids, bases, and buffers Flashcards
le chateliers principle
when a system in a state of dynamic equilibrium is disturbed, it will react to re-establish the equilibrium condition
a system is in a state of equilibrium when
there is a balance between reactants and products
the state of equilibrium is defined by
thermodynamics
as K (equilibrium constant) increases, the reaction tends to increasingly favor ___
products
as K (equilibrium constant) decreases, the reaction tends to increasingly favor __
starting materials
if you add products, the equilibrium will shift toward
reactants
if you remove products, the equilibrium will shift toward
products
most generally useful definition of an amide is the
bronstead definition
an acid is a proton (hydrogen ion) ___
donor
a base is a proton (hydrogen ion) ___
acceptor
when an acid donates a proton, it is converted into its
conjugate base
when a base accepts a proton, it is converted into its
conjugate acid
hydrogen and chloride are
acid base pairs
amphoteric species
can behave as either an acid or a base
the stronger the acid, the weaker the
conjugate base
the weaker the acid, the stronger the
conjugate base
a ph buffer
a solution that resists changes in ph
the ___ is used to determine the ratio of a weak acid to its conjugate base at a given ph
henderson hasselbach equation
when the concentration of a weak acid and its conjugate base are equal,
the ph is equal to the pKa
nonionized =
lipid soluble
ionized form of a drug is ___ soluble
water
what is the ph of the body
7.4
acid + acid =
nonionized
if you see a salt drug - sodium drug, calcium drug, magnesium drug, you would recognize the drug as
the salt form of a weak acid
base + base =
nonionized
if you see salt: “drug” chloride, “drug” sulfate, recognize them as
the salt form of a weak base
the pk50 of a weak acid/base is
the ph at which 50% is ionized and 50% is non-ionized
the greater the ___ portion of the drug, the greater the transfer to brain and fetus
non-ionized
the nonionized form of a weak acid is the ___ and the ionized form is its ___
acid, conjugate base
the non-ionized form of a weak base is the ___ and then ionized portion is the ____
base . conjugate acid
a substance that accepts a hydrogen ion is said to be
protonated
examples of weak acid drugs
thiopental, barbiturates, prop
examples of weak base drugs
lidocaine (locals), morphine (opioids), versed (benzos), propofol:?
trapping of local anesthetics in fetal circulation
the ph of the fetus is lower than maternal, the circulating non-ionized drug crosses the placental barrier. once in the fetus, equilibrium is reestablished, with a greater % ionized and trapped in fetal circulation
