goc neet

Which of the following carbocations is the most stable?

• CH₃⁺

• CH₃CH₂⁺

• (CH₃)₂CH⁺

• (CH₃)₃C⁺

The correct decreasing order of +I effect of the following groups is:

• –CH₃, –C₂H₅, –iPr, –tBu

• –tBu, –iPr, –C₂H₅, –CH₃

• –C₂H₅, –tBu, –CH₃, –iPr

• –iPr, –C₂H₅, –CH₃, –tBu

Answer explanation

(The larger the alkyl group, the stronger the +I effect).

Which of the following is the correct order of the –I effect of the given groups?

• –NO₂ > –F > –OH > –NH₂

• –F > –NO₂ > –OH > –NH₂

• –OH > –NO₂ > –F > –NH₂

• –NH₂ > –OH > –F > –NO₂

Answer explanation

–NO₂ > –F > –OH > –NH₂ (Strongly electronegative groups show stronger –I effects).

Which of the following is the correct order of stability of carbanions?

• CH₃⁻ > CH₃CH₂⁻ > (CH₃)₂CH⁻ > (CH₃)₃C⁻

• (CH₃)₃C⁻ > (CH₃)₂CH⁻ > CH₃CH₂⁻ > CH₃⁻

• CH₃⁻ > CH₃CH₂⁻ > (CH₃)₂CH⁻ > (CH₃)₃C⁻

• CH₃CH₂⁻ > CH₃⁻ > (CH₃)₂CH⁻ > (CH₃)₃C⁻

Answer explanation

CH₃⁻ > CH₃CH₂⁻ > (CH₃)₂CH⁻ > (CH₃)₃C⁻ (Carbanions are destabilized by alkyl groups due to +I effect).

Which of the following species is the most nucleophilic?

• CH₃O⁻

• CH₃OH

• CH₃COO⁻

• H₂O

Answer explanation

CH₃O⁻ (Negative charge and absence of resonance make it the strongest nucleophile).

The correct order of stability of free radicals is:

• CH₃• > CH₃CH₂• > (CH₃)₂CH• > (CH₃)₃C•

• (CH₃)₃C• > (CH₃)₂CH• > CH₃CH₂• > CH₃•

• CH₃CH₂• > (CH₃)₂CH• > (CH₃)₃C• > CH₃•

• CH₃• > CH₃CH₂• > (CH₃)₃C• > (CH₃)₂CH•

Answer explanation

(CH₃)₃C• > (CH₃)₂CH• > CH₃CH₂• > CH₃• (Stabilization by hyperconjugation and +I effect).

The correct order of mesomeric effect (–M effect) strength is:

• –NO₂ > –CN > –COOH > –OH

• –OH > –COOH > –CN > –NO₂

• –COOH > –NO₂ > –CN > –OH

• –CN > –OH > –NO₂ > –COOH

Answer explanation

–NO₂ > –CN > –COOH > –OH (Electron-withdrawing groups show stronger –M effects).

Which of the following is the correct order of nucleophilicity?

• F⁻ > Cl⁻ > Br⁻ > I⁻ (in polar protic solvent)

• I⁻ > Br⁻ > Cl⁻ > F⁻ (in polar protic solvent)

• Cl⁻ > F⁻ > Br⁻ > I⁻ (in polar aprotic solvent)

• Both (2) and (3)

Answer explanation

Both (2) and (3) (Nucleophilicity increases down the group in protic solvents and decreases in aprotic solvents).

Which of the following will show the strongest +M effect?

• –NH₂

• –OH

• –OCH₃

• –NO₂

Answer explanation

–NH₂ (Lone pair donation by resonance makes it the strongest +M group).

The correct order of acid strength among the following is:

• Phenol > p-Nitrophenol > p-Methylphenol > p-Methoxyphenol

• p-Nitrophenol > Phenol > p-Methylphenol > p-Methoxyphenol

• p-Methylphenol > Phenol > p-Methoxyphenol > p-Nitrophenol

• Phenol > p-Methoxyphenol > p-Methylphenol > p-Nitrophenol

Answer explanation

p-Nitrophenol > Phenol > p-Methylphenol > p-Methoxyphenol (Electron-withdrawing groups increase acidity).