Quiz Bank 4 - Quiz Bank 4 1 N6-Isopentenyladenine shown...

Quiz Bank 4
1. N
6
-Isopentenyladenine, shown below is an unusual base found in RNA. What is
its relationship with caffeine? (Experiment 4)
2. What technique is best used to purify a compound that readily forms hydrates and
explain why? (Chapter 12)
3. What is the purpose of lowering the pressure in sublimation? (Chapter 12)
4. One hundred milligrams of compound A (K
p
= 4.15 x 10
-1
) is dissolved in 2 mL
of H
2
O and subsequently extracted with an equal volume of dichloromethane
(DCM). What percentage of compound A is recovered from this single
extraction? If the resulting aqueous layer is extracted with another 2.0 mL of
DCM, what is the total percent recovery based on these two extractions? (Chapter
8)
5. A student accidentally mixes caffeine with benzoic acid. Outline a procedure
that could be followed to enable the students to isolate both compounds in
relatively pure form.
6. An aqueous solution of compound X (1 mg) in water (100mL) was extracted with
chloroform. After extracting, the chloroform layer contained 0.95 mg of
compound X.