E. A medical facility received 100.0g of Fluorine-18. After 8 hours, there was only 6.25g left. What is the half-life of Fluorine-18?

23

Predict the approximate ratio peaks in the mass spectrum of 1,2-Dichloroethane at m/z values 98, 100, and 102.

94

A purified protein fraction has a total sample volume of 360 µL.  The sample has a corrected A280 of 0.484, and the blank corrected A280 was 0.052.  (Both values were measured with a path length of 1.00 cm.)  If 5.00 µL of the sample was used in a reaction, calculate the mass of protein in the reaction (in µg).

I. Write a balanced chemical reaction, complete with chemical structures, to show the hydrolysis of iso-C to U. II. Draw the mechanism by which iso-G converts to its "minor tautomeric form complementary to U."  You may propose either an acid or base catalyst. III. Draw chemical structures of the minor tautomeric form of iso-guanine (iso-G) and uracil (U), showing the non-covalent bonding (H-bonding) interactions between them.