Which of the following trends in nucleophilicity are correct?
I. Everything else being equal, a negatively charged nucleophile will react faster than a neutral one.
II. Generally, species containing elements of high electronegativity are good nucleophiles.
III. Anionic nucleophiles are more reactive in polar and aprotic solvents than in polar and protic solvents
IV. Generally, nucleophilicity is increasing with the increase in size of an atom.
V. Bulky groups adjacent to the nucleophilic atom enhance the nucleophilicity and reactivity of the species.

Question

Which of the following trends in nucleophilicity are correct? 
I. Everything else being equal, a negatively charged nucleophile will react faster than a neutral one.
II. Generally, species containing elements of high electronegativity are good nucleophiles.
III. Anionic nucleophiles are more reactive in polar and aprotic solvents than in polar and protic solvents
IV. Generally, nucleophilicity is increasing with the increase in size of an atom.
V. Bulky groups adjacent to the nucleophilic atom enhance the nucleophilicity and reactivity of the species.

Quizplus · Accepted Answer

I. Everything else being equal, a negatively charged nucleophile will react faster than a neutral one. This is because a negatively charged nucleophile has more electron density and is thus more likely to react with an electrophile.
II. Generally, species containing elements of high electronegativity are good nucleophiles. This statement is false since electronegativity reflects the ability of an atom to attract electron density towards itself and not give electron density to other atoms.
III. Anionic nucleophiles are more reactive in polar and aprotic solvents than in polar and protic solvents. This is because protic solvents can hydrogen bond with anionic species, reducing their nucleophilicity, while aprotic solvents cannot do so.
IV. Generally, nucleophilicity is increasing with the increase in size of an atom. This is because larger atoms are less electronegative, and their valence electrons are farther away from the nucleus, making them more easily accessible to participate in chemical reactions.
V. Bulky groups adjacent to the nucleophilic atom enhance the nucleophilicity and reactivity of the species. This is because bulky groups can shield the electronegative atoms from the solvent, which reduces their ability to accept a proton and thus enhances their nucleophilicity.

Which of the Following Trends in Nucleophilicity Are Correct