Solution: Phenylenediamine (pictured below) is mainly used as a component of engineering polymers and composites. It is also an ingredient in hair dyes and is occasionally used as a substitute for henna.
How many molecules are in a 2.00 g of phenylenediamine?
a. 1.30 x 1028
b. 1.11 x 1022
c. 3.59 x 10-20
d. 3.07 x 10-24