Polyesters are formed from the reaction of
a.
a diamine and a dicarboxylic acid
b.
an alkene and a dicarboxylic acid
c.
a diol and a dicarboxylic acid
d.
a diol and an amino acid

The answer is C. a diol and a dicarboxylic acid

Explanation:

Because Esterification (formation of an ester) is a process that requires an alcohol to react with a carboxylic acid.

Polyester means many ester units.

one alcohol + one carboxylic acid make one ester

thus more than one of each functional groups will make more than on ester unit.

That is why diol (2OH functional groups) + dicarboxylic acid (2 Carboxyl groups) will make polyesters.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.