Question

Rank the relative nucleophilicity of halide ions in acetic acid solution, How is acetic acid classified?

Rank the relative nucleophilicity of halide ions in acetic acid solution.

Answer 1

Concepts and reason

Nucleophilicity: The rate at which the nucleophile attacks the respective carbon atom that is measured at standard state conditions. It is a kinetic property. The order of nucleophilicity depends on the type of solvent present. Polar solvent and non – polar solvents are the two types of solvents.

Polar solvents are further classified into:

• Polar protic solvent.

• Polar aprotic solvent.

Fundamentals

Polar protic solvents: These solvents contain either an ${\rm{O - H}}\,{\rm{or an}}\,{\rm{N - H}}$ bond. These solvents can participate in hydrogen bonding. These solvents have strong dipole moments. Example: Water and methanol.

Polar aprotic solvents: These solvents cannot contain heteroatoms and they may have hydrogen atoms somewhere but they cannot participate in hydrogen bonding. Example: DMSO, acetonitrile.

Most nucleophilic to least nucleophilic in acetic acid solution:

${{\rm{I}}^{\rm{ - }}}\,{\rm{ > }}\,\,{\rm{B}}{{\rm{r}}^{\rm{ - }}}\,{\rm{ > }}\,{\rm{C}}{{\rm{l}}^{\rm{ - }}}{\rm{ > }}\,{{\rm{F}}^{\rm{ - }}}$

Polar protic solvent.

Ans:

Nucleophilicity of halide ions in an acetic acid solution:

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Acetic acid is classified as: