How would you expect phosphorus pentachloride to react with ethanol? How does this reaction resemble the reaction of phosphorus pentachloride with ethanoic acid?

Question

Naomi Aronson · Accepted Answer

With alcohol:
#PCl_5+ROH rarr O=PCl_3 + RCl + HCl# When acid is present: #PCl_5+RC(=O)OH rarr O=PCl_3 + RC(=O)Cl + HCl# #"Phosphorus pentachloride"# is a halogenating agent. It is rarely used these days, as you have to remove the #"pockle3"# after the reaction. #PCl_5# is very water sensitive, and a bit hard to handle. A better alternative might be #"thionyl chloride"#, which you can pour out of a bottle and distill off: #RCO_2H + SOCl_2 + Delta rarr RC(=O)Cl + SO_2uarr + HCluarr#

Natalie Anton · Answer

undefined This reaction is similar to the reaction of phosphorus pentachloride with ethanoic acid in that both involve the replacement of oxygen with chlorine, resulting in the formation of an alkyl chloride and a phosphoric acid derivative. Phosphorus pentachloride (PCl5) would react with ethanol to produce ethyl chloride (C2H5Cl) and phosphoric acid (H3PO4).