PHA 317: Pharmaceutics I Exam 2
UPDATED ACTUAL Questions and
CORRECT Answers
TRUE OR FALSE: The lower the pKa value for an acid, the greater the hydronium ion
concentration it would produce on being added to water. - CORRECT ANSWER - True
TRUE OR FALSE: Stronger bases, such as guanethidine (pKa >11) are ionized throughout the
GI tract and tend to be well absorbed throughout the GI tract. - CORRECT ANSWER -
False - strong bases are ionized in the GI tract and therefore poorly absorbed throughout the GI
tract
What is the pH of a buffer containing 0.1-M acetic acid (pKa 4.8) and 0.08 M sodium acetate? -
CORRECT ANSWER - 4.7
unionized molecules are soluble where? - CORRECT ANSWER - lipid bilayer - can cross
blood-brain barrier
TRUE OR FALSE: most weak bases are poorly absorbed in the stomach, because they are
present largely in the ionized form at pH 1-2. - CORRECT ANSWER - True
TRUE OR FALSE: weakly basic drugs with a pKa of less than 4, such as dapsone, diazepam,
and chlordiazepoxide, are essentially un-ionized throught the GI tract. - CORRECT
ANSWER - True
TRUE OR FALSE: The Beer-Lambert Law is the basis for deriving quantitative information
from an absorption spectrum. - CORRECT ANSWER - True
TRUE OR FALSE: in regards to Beer-Lambert law, the constant k, is called molar absorption
coefficient if unit concentration (c) is mole/liter. - CORRECT ANSWER - True
, TRUE OR FALSE: in regards to Beer-Lambert law, the constant k, is called specific absorption
coefficient if unit concentration (c) is gram/liter. - CORRECT ANSWER - True
TRUE OR FALSE: the ratio of absorbance of DNA at 260nm to 280nm is 1.8 and 2 for RNA -
CORRECT ANSWER - True
TRUE OR FALSE: Tyrosine and Tryptophan are most prominent amino acids capable of
producing fluorescence when exposed to radiation of wavelength 190nm. - CORRECT
ANSWER - False - proteins are absormed at 280nm
In an aromatic system, why does electronegativity lead to stronger UV absorption? - CORRECT
ANSWER - electronegativity delocalizes the bonded electrons
TRUE OR FALSE: in unsaturated compounds, the pi electrons are loosely held in comparison to
sigma electrons. Therefore, less energy is required to excite pi electrons and absorbs more energy
- CORRECT ANSWER - True
TRUE OR FALSE: phosphorescence is the energy released when triplet excited electrons return
to ground state. - CORRECT ANSWER - True
TRUE OR FALSE: phosphorescence is a slower process and has a longer lifetime than
fluorescence. - CORRECT ANSWER - True
Rule of 5? - CORRECT ANSWER - 1. MW>750
2. H bond donors >5
3. H bond acceptors >5
4. log P >5
TRUE OR FALSE: protons exist in different environments and possess different magnetic field
strength. - CORRECT ANSWER - True
UPDATED ACTUAL Questions and
CORRECT Answers
TRUE OR FALSE: The lower the pKa value for an acid, the greater the hydronium ion
concentration it would produce on being added to water. - CORRECT ANSWER - True
TRUE OR FALSE: Stronger bases, such as guanethidine (pKa >11) are ionized throughout the
GI tract and tend to be well absorbed throughout the GI tract. - CORRECT ANSWER -
False - strong bases are ionized in the GI tract and therefore poorly absorbed throughout the GI
tract
What is the pH of a buffer containing 0.1-M acetic acid (pKa 4.8) and 0.08 M sodium acetate? -
CORRECT ANSWER - 4.7
unionized molecules are soluble where? - CORRECT ANSWER - lipid bilayer - can cross
blood-brain barrier
TRUE OR FALSE: most weak bases are poorly absorbed in the stomach, because they are
present largely in the ionized form at pH 1-2. - CORRECT ANSWER - True
TRUE OR FALSE: weakly basic drugs with a pKa of less than 4, such as dapsone, diazepam,
and chlordiazepoxide, are essentially un-ionized throught the GI tract. - CORRECT
ANSWER - True
TRUE OR FALSE: The Beer-Lambert Law is the basis for deriving quantitative information
from an absorption spectrum. - CORRECT ANSWER - True
TRUE OR FALSE: in regards to Beer-Lambert law, the constant k, is called molar absorption
coefficient if unit concentration (c) is mole/liter. - CORRECT ANSWER - True
, TRUE OR FALSE: in regards to Beer-Lambert law, the constant k, is called specific absorption
coefficient if unit concentration (c) is gram/liter. - CORRECT ANSWER - True
TRUE OR FALSE: the ratio of absorbance of DNA at 260nm to 280nm is 1.8 and 2 for RNA -
CORRECT ANSWER - True
TRUE OR FALSE: Tyrosine and Tryptophan are most prominent amino acids capable of
producing fluorescence when exposed to radiation of wavelength 190nm. - CORRECT
ANSWER - False - proteins are absormed at 280nm
In an aromatic system, why does electronegativity lead to stronger UV absorption? - CORRECT
ANSWER - electronegativity delocalizes the bonded electrons
TRUE OR FALSE: in unsaturated compounds, the pi electrons are loosely held in comparison to
sigma electrons. Therefore, less energy is required to excite pi electrons and absorbs more energy
- CORRECT ANSWER - True
TRUE OR FALSE: phosphorescence is the energy released when triplet excited electrons return
to ground state. - CORRECT ANSWER - True
TRUE OR FALSE: phosphorescence is a slower process and has a longer lifetime than
fluorescence. - CORRECT ANSWER - True
Rule of 5? - CORRECT ANSWER - 1. MW>750
2. H bond donors >5
3. H bond acceptors >5
4. log P >5
TRUE OR FALSE: protons exist in different environments and possess different magnetic field
strength. - CORRECT ANSWER - True
