Which one is NOT a nucleophile?
Correct answer: A. BH3
- A. BH3
- B. NH3
- C. -NH2
- D. -OH
Explanation
A nucleophile is a chemical species that donates a lone pair of electrons to form a chemical bond to another electron deficient species. It therefore must always possess at least one lone pair in order to do this. In BH3, boron it is bonded to three hydrogen atoms. It has a valency of 3 so all of its valence electrons are used in bonding. Since no lone pairs are present, it cannot act as a nucleophile. Therefore, option A is the correct answer.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Nucleophilic Substitution
Nucleophilic substitution replaces a leaving group in an alkyl halide when an electron-rich nucleophile attacks the carbon atom. The topic compares SN1 and SN2 mechanisms, including reaction conditions, substrate structure, solvent effects, nucleophile strength, carbocation formation and stereochemical changes, and distinguishes substitution from elimination.
Practise Alkyl Halides
458 free Alkyl Halides MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Chemistry questions like this
Chemistry is on 14 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Nucleophilic Substitution questions
The rate of SN2 reaction becomes doubled if the _.
Which of the following intermediate has the complete octet around the carbon atom?
What is true about the mechanisms I and II
Which class of halogenoalkane can react with alkali by an SN2 mechanism?
Example of nucleophile is:
During the course of an SN1 reaction, the intermediate species formed is: