Answer
(a) 558.63 $u$
(b) 444.51 $u$
(c) 321.82 $u$
Work Step by Step
(a) Molecular weight ($C_{33}H_{35}FN_2O_5$):
12.01* 33 + 1.008* 35 + 19.00* 1 + 14.01* 2 + 16* 5 = 558.63 $u$
(b) Molecular weight ($C_{22}H_{27}F_3O_4S$):
12.01* 22 + 1.008* 27 + 19* 3 + 16.00* 4 + 32.07* 1 = 444.51 $u$
(c) Molecular weight ($C_{16}H_{16}ClNO_2S$):
12.01* 16 + 1.008* 16 + 35.45* 1 + 14.01* 1 + 16.00* 2 + 32.07* 1 = 321.82 $u$
