Week 1 Flashcards
Is benzocaine acidic or basic?
basic
is amphetamine acidic or basic?
basic
is acetaminophen acidic or basic?
acidic
is clotrimazole acidic or basic?
basic
T/F any drug with acid-base character will always exist in both acidic and basic forms
True
The amount of drug in either unionized or ionized form depends on the ___ of the acid and the ___ of the medium
pka, ph
T/F acids/bases both exist in both charged and uncharged forms
True
the ionized form of a drug is more _____ soluble than the unionized form
water
the unionized form of a drug is more _____ soluble than the ionized form
lipid
the acidic form of a drug is greater when pH is?
less than 7
the basic form of a drug is greater when pH is?
greater than 7
define drug absorption
movement of drug from site of administration into the bloodstream
in order for drugs to cross lipophilic barriers, some of it is requires to be in its _____ form. Why?
unionized
unionized form is more lipid soluble, so it can cross the lipid bilayer
drug absorption is greatly dependent on? (what form of drug)
amount of drug in unionized form at site of absorption
Define renal drug excretion
elimination of drug from the body by the kidney
if a drug is being excreted from the body, which soluble form is more easily excreted?
water soluble compounds
if a drug is in its unionized form in the kidneys, what outcome can happen a part from excretion?
Unionized drug can be reabsorbed into circulation to provide its therapeutic effect again
if a drug is in its ionized form in the kidneys, what is the outcome?
ionized drug is excreted in the urine
who’s concept describes an acid as a substance which generates a hydrogen proton (H+)?
Arrhenius Concept
who’s concept describes a base as a substance which generates a hydroxide anion (OH-)
Arrhenius Concept
who’s concept describes a neutralization reaction as resulting in the formation of water and salt?
Arrhenius Concept
what is the flaw in the Arrhenius Concept?
some basic substances do not have OH-
who’s concept describes an acid as a substance which is capable of donating a hydrogen proton to a conjugate base?
Bronsted-Lowry Concept
who’s concept describes a base as a substance which is capable of accepting a hydrogen proton (H+) producing a conjugate acid?
Bronsted-Lowry Concept
who’s concept describes a neutralization reaction being when the reaction between acid and base results in the formation of a conjugate base and conjugate acid?
Bronsted-Lowry Concept
what does it mean to say water is amphoteric
can function as both a proton acceptor and proton donor
who’s concept describes an acid as a substance which is capable of accepting an electron pair?
Lewis Concept
who’s concept describes a base as a substance which is capable of donating an electron pair?
Lewis Concept
who’s concept describes a neutralization reaction as a reaction between an acid and base forming an addition product as the electrons from the electron donating base are picked up by the electron accepting acid?
Lewis Concept
Reaction between an acid and base results in the formation of a?
conjugate base and
conjugate acid
what is molarity?
concentration measured by the number of moles of solute per liter of solution
what does the pH tell you about an aqueous solution?
the concentration of a hydrogen proton (H+) or hydronium anion (H3O+) already in the medium
each whole pH value is ___ times more acidic/basic than the following value, for example, an acid with a pH of 2 is ____ times more acidic than a solution with a pH of 5
ten, 1000
what information does the pOH scale provide?
the concentration of OH- ions in a solution
how do you calculate pOH given the pH?
pOH= 14-pH
T/F almost every acid and base encountered in pharmacy is a strong acid or strong base
False, weak acid or weak base
what is Le Chatelier’s principle?
if a chemical system at equilibrium experiences a change, than the equilibrium shifts to counteract the change and a new equilibrium is established
a larger Ka means that the acid has a ______ tendency to donate its H+, meaning its a stronger or weaker acid?
stronger, stronger acid
the lower the pKa value the ____ the acid
stronger
the higher the pKa value the ____ the acid
weaker
what does the pKa value tell you? is it a value that is changeable?
how willing/unwilling an acid is to donate a proton when dissolved in water
no
what does the pH value tell you? is it a value that is changeable?
the concentration of hydrogen proton in the solution
yes
what is a polyprotic compound?
a molecule that contains several different ionizable groups
how many protons can a diprotic acid donate?
two hydrogen protons
how many protons can a triprotic acid donate?
three hydrogen protons
the stronger an acid, the ____ its conjugate base will be
weaker
the weaker an acid, the ____ its conjugate base will be
stronger
the weaker the acid, the ___ time it spends in acid form and ____ time it spends in conjugate base form
more, less
an aliphatic carboxylic group (R-COOH) is a common weak acid or base?
acid
an aromatic carboxylic group (benzene ring with COOH attached) is a common weak acid or base?
acid
a phenol group (benzene ring with OH attached) is a common weak acid or base?
acid
a sulfonamide group (R-SOONH2) is a common weak acid or base?
acid
an imide group (O=C-NH-C=O) is a common weak acid or base?
acid
a thiol group (R-SH) is a common weak acid or base?
acid
what is the Henderson-Hasselbalch equation?
pH = pKa + log [Conj, Base] / [Acid]
when the pH of the medium is equal to the pKa of the acid, the drug exists __% in the ionized form and __% in the unionized form
50,50
a primary amine (R-NH2) is a common weak acid or base?
weak base
a secondary amine (R-NH-R) is a common weak acid or base?
weak base
a tertiary amine (R-N-R)
I
R
is a common weak acid or base?
weak base
a pyridine (benzene ring with one carbon replaced by N) is a common weak acid or base?
weak base
an imidazole (pentagon ring with two Ns replacing C) is a common weak acid or base?
weak base
what does Kb measure?
weak base strength
the pKa for a weak base is actually the pKa of the ________ of that base
conjugate acid
the lower the pKa the ___ the acid and the ___ the base
stronger, weaker
the higher the pKa value the ___ the acid and the ___ the base
weaker, stronger
The stronger an acid, the ____ its conjugate base will be
weaker
the stronger a base, the ____ its conjugate acid will be
weaker
a pKa less than two is a strong or weak acid?
strong
a pKa greater than 12 is a strong or weak base?
strong
a pKa greater than 3 is a strong or weak acid?
weak
a pKa less than 11 is a strong or weak base?
weak
