Aromatic molecules contain ________ π electrons.

A) no
B) 4n + 1 (with n an integer)
C) 4n + 2 (with n an integer)
D) 4n (with n an integer)
E) unpaired

An ________ molecular ion peak usually indicates the presence of an odd number of nitrogen atoms in the molecule.

A) even
B) odd
C) intense
D) absent

Which of the molecules below can hydrogen bond to another of the same compound?

A) CH₃CH₂OCH₂CH₃
B) CH₃CH₂COOCH₃
C) (CH₃CH₂) ₂CHOH
D) CH₃CH₂COCH₂CH₃
E) all of the above

Which of the following amino acids has its isoelectric point at the highest pH?

A) glycine
B) aspartic acid
C) valine
D) arginine
E) methionine