Which is the correct arrow pushing formalism for the following acid/base reaction? <img src="https://media.pearsoncmg.com/ph/esm/ecs_mullins_organic1e/msa/content/practice-test/img/Ch04_Q03_QT.jpg" alt="The figure illustrates a reversible reaction. The reaction contains two reactants and two products. The first reactant is H 2 N in which N has 2 lone pairs of electrons and carries a negative charge. The second reactant has the following structure: A 3-carbon alkyne chain is depicted as a line structure using three parallel lines between C 1 and C 2 and 1 line between C 2 and C 3. C 1 is single bonded to H on the left. The first product is H 3 N in which N has 1 lone pair of electrons. The second product has the following structure: A 3-carbon alkyne chain is depicted as a line structure using three parallel lines between C 1 and C 2 and 1 line between C 2 and C 3. C 1 has 1 lone pair of electrons and carries a negative charge." />

The reaction contains two reactants. The first reactant is H 2 N in which N has 2 lone pairs of electrons and carries a negative charge. The second reactant has the following structure: A 3-carbon alkyne chain is depicted as a line structure using three parallel lines between C 1 and C 2 and 1 line between C 2 and C 3. C 1 is single bonded to H on the left. A curved arrow from a lone pair of electrons on N points to H in the second reactant. A second curved arrow from H in the second reactant points to the single bond between H and C 1." />

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1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

3. Acids and Bases

Acids and Bases

Organic Chemistry

3. Acids and Bases

Acids and Bases

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Multiple Choice

Which is the correct arrow pushing formalism for the following acid/base reaction?

The figure illustrates an arrow pushing mechanism. The reaction contains two reactants. The first reactant is H 2 N in which N has 2 lone pairs of electrons and carries a negative charge. The second reactant has the following structure: A 3-carbon alkyne chain is depicted as a line structure using three parallel lines between C 1 and C 2 and 1 line between C 2 and C 3. C 1 is single bonded to H on the left. A curved arrow from H in the second reactant points to N in the first reactant.

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Verified step by step guidance

Identify the reactants: The first reactant is the amide ion (H₂N⁻) with a negative charge on nitrogen, which has two lone pairs of electrons. The second reactant is a terminal alkyne (H-C≡C-R) where R is a carbon chain.

Recognize the role of each reactant: The amide ion acts as a base, and the terminal alkyne acts as an acid in this reaction.

Determine the direction of electron flow: The lone pair of electrons on the nitrogen of the amide ion will attack the hydrogen atom of the terminal alkyne.

Draw the first curved arrow: This arrow should start from the lone pair on the nitrogen and point towards the hydrogen atom of the alkyne, indicating the formation of a new N-H bond.

Draw the second curved arrow: This arrow should start from the H-C bond of the alkyne and point towards the carbon atom, indicating the breaking of the H-C bond and the formation of a carbanion (C⁻).