Exam 1 Chp Q Flashcards
Draw three examples of types of molecules that can form hydrogen bonds.
Many molecules can form hydrogen bonds. Examples might be H2O, CH3OH, or NH3
Rationalize the fact that hydrogen bonding has not been observed between CH4 molecules.
The C-H bond is not sufficiently polar for greatly unequal distribution of electrons at it’s two ends. Also, there are no unshared pairs of electrons to serve as hydrogen bond acceptors.
What are the requirements for molecules to form hydrogen bonds? What atoms must be present and involved in such bonds?
For a bond to be called a hydrogen bond it must have a hydrogen covalently bonded to O,N, or F. This hydrogen then forms a hydrogen bond with another O,N, or F.
Many properties of acetic acid can be rationalized in terms of a hydrogen bonded dimer. Propose a structure for such a dimer.
In a hydrogen bonded dimer of acetic acid, the -OH portion of the carboxyl group on molecule 1 is hydrogen bonded to the - C double bond O portion of the carboxyl group on molecule 2 and vice versa.
What would be the pH of the solution described in question 33?
Any buffer that has equal concentrations of the acid and basic forms has a pH equal to it’s pKa. Therefore the buffer from question 33 has a pH of 8.3
How do the resonance structures of the peptide group contribute to the planar arrangement of this group of atoms?
The resonance structures contribute to the planar arrangement by giving the CON bond partial double bound character.
Define denaturation in terms of the effects of secondary, tertiary, and quaternary structure.
When a protein is denatured, the interactions that determine secondary, tertiary, and quaternary structure are overcome by the presence of the denaturing agent. Only the primary structure remains intact.
