Question

Total number of nucleophiles from the following is: \(\text{NH}_3, PhSH, (H_3C_2S)_2, H_2C = CH_2, OH−, H_3O+, (CH_3)_2CO, NCH_3\)

• A. 5
• B. 6
• C. 4
• D. 7

Hint:

A nucleophile is typically an electron-rich species capable of donating electrons. Common examples include amines, thiols, and hydroxide ions.

Answer 1

The Correct Option is A

To identify the total number of nucleophiles among the provided species, it is necessary to define a nucleophile. A nucleophile is a chemical entity that donates an electron pair to form a covalent bond during a chemical reaction. Nucleophiles typically exhibit a negative charge or possess neutral atoms with available lone pairs of electrons.

The classification of each species is as follows:

• \(\text{NH}_3\) (Ammonia): Ammonia functions as a nucleophile due to the presence of a lone electron pair on its nitrogen atom.
• \(PhSH\) (Thiophenol): The sulfur atom in thiophenol, which has a lone pair of electrons, renders it a nucleophile.
• \((H_3C_2S)_2\) (Diethyl sulfide): This molecule contains sulfur with lone pairs, classifying it as a nucleophile.
• \(H_2C = CH_2\) (Ethene): Ethene, an alkene, can act as a nucleophile in specific reactions, such as epoxidation, owing to the electron density within its \(\pi\) bond.
• \(OH^-\) (Hydroxide ion): As a negatively charged species with lone pair electrons, it is a potent nucleophile.
• \(H_3O^+\) (Hydronium ion): This species is not a nucleophile; it is an electrophile due to its electron-deficient nature.
• \((CH_3)_2CO\) (Acetone): Acetone generally does not act as a nucleophile in standard reactions. It typically serves as a solvent or an electrophile due to the carbonyl group.
• \(NCH_3\) (Methyl isocyanide): Generally considered a nucleophile due to lone pairs on nitrogen, although less common.

Enumerating the nucleophiles: \(\text{NH}_3\), \(PhSH\), \((H_3C_2S)_2\), \(H_2C = CH_2\), and \(OH^-\) are identified as nucleophiles. Therefore, the total count of nucleophiles is 5.

Answer: 5