I could use some help on this question. I think the answer is choice E, but im not sure.
Alcohols can function as both nucleophiles and as electrophiles in various reaction conditions. Which of the following statements is/are true.
a)When R-O-H is a nucleophile, the O-H bond is broken, generally.
b)When R-O-H is an electrophile the R-O bond is broken, generally
c)When R-O-H is an electrophile the OH should be pronated because OH is a poor leaving group.
d)When R-O-H is a nucleophile a base, with a pKa > than ROH's can be used to abstract the alcoholic proton to create the alkoxide, a stronger nucleophile.
e)All of the above are true
To determine the correct answer, let's analyze each statement and determine if it is true or false.
a) When R-O-H is a nucleophile, the O-H bond is broken, generally.
This statement is true. In nucleophilic reactions, the lone pair on the oxygen atom in the alcohol attacks an electrophilic site, leading to the breaking of the O-H bond.
b) When R-O-H is an electrophile, the R-O bond is broken, generally.
This statement is false. In electrophilic reactions, the R-O bond is not typically broken. Instead, the electrophile reacts with the electron-rich site in the molecule, such as the lone pair on the oxygen atom in nucleophilic attacks.
c) When R-O-H is an electrophile, the OH should be protonated because OH is a poor leaving group.
This statement is true. Under normal conditions, the hydroxyl group (OH) is a poor leaving group. Therefore, it is often protonated to form water, making it a better leaving group.
d) When R-O-H is a nucleophile, a base with a pKa greater than ROH's can be used to abstract the alcoholic proton to create the alkoxide, a stronger nucleophile.
This statement is true. Nucleophilic reactions can involve the abstraction of the alcoholic proton with a stronger base (generally indicated by a higher pKa) to create an alkoxide ion. The alkoxide ion is a stronger nucleophile compared to the original alcohol.
After analyzing each statement, we see that statements a, c, and d are true. However, statement b is false. Therefore, the correct answer would be choice D, not choice E.