Which is a better leaving group, OH or SH?

How many atoms are in 1.4 mil of phosphorus trifluoride (pf3)

What is the total reduction potential of a cell in which potassium (k) is reduced and copper (cu) is oxidized? a. 2.59 v b. 3.27 v c. -3.27 v d.-2.59 v

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct