Which is the most stable base in each pair? (c) NH 3 vs. H 2 O

Welcome back, everyone choose the more stable base between the given compounds. H two and H two S. So let's consider them. If we want to identify a more stable base, we can essentially say that we're looking for a weaker base, right? Because weaker bases are more stable. And we also know that the weaker the base, the stronger the acid, right? So if it has a low baity, then it will have high acidity and vice versa. So a weaker base implies a stronger as sub which one of the 2 H2O or H two S is a stronger acid. Well, let's take one acidic hydrogen or H2O. We can say we are analyzing hoh and for H two S, we're analyzing HSH, the more acidic hydrogen will be bonded to a larger atom, right? Because we are considering oxygen and sulfur, they both belong to the group six A. And if we go down the group, we have oxygen and sulfur, we know that going down the group, the atomic radius increases the greater the radius, the greater the distance between the acidic hydrogen and the hetero atom. And the greater the distance, the lower the attraction force based on the Kam's law. And the lower the attraction force, the easier it is for us to break the bond meaning to is more acidic because the radius of sulfur is larger than the radius of oxygen. So we have that larger distance and a weaker attraction force. Therefore, we know that H two S is more acidic. So let's keep this in mind. And if it is more acidic or it is a stronger acid, then it is a weaker base. And as a result, a more stable base, so the answer would be option bh two S is a more stable base between the given compounds. Thank you for watching.

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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

Ranking Acidity

Organic Chemistry

3. Acids and Bases

Ranking Acidity

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Problem 3c

Textbook Question

Which is the most stable base in each pair?
(c) NH₃ vs. H₂O

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Compare the basicity of NH₃ (ammonia) and H₂O (water) by analyzing their ability to donate a lone pair of electrons to accept a proton (H⁺). A stronger base will have a greater tendency to donate its lone pair.

Examine the electronegativity of the central atoms in each molecule. Nitrogen (N) in NH₃ is less electronegative than oxygen (O) in H₂O. This means nitrogen holds onto its lone pair less tightly, making it more available for protonation.

Consider the stability of the conjugate acids formed when each base accepts a proton. NH₃ forms NH₄⁺ (ammonium ion), while H₂O forms H₃O⁺ (hydronium ion). The stability of the conjugate acid can influence the basicity of the original base.

Analyze the molecular structure and hydrogen bonding. H₂O can form stronger hydrogen bonds due to its higher electronegativity, which can stabilize the molecule and reduce its basicity compared to NH₃.

Conclude that NH₃ is the more stable base in this pair because its lone pair is more readily available for protonation, and its conjugate acid (NH₄⁺) is relatively stable.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Acid-Base Theory

Acid-base theory explains the behavior of acids and bases in chemical reactions. According to the Brønsted-Lowry theory, an acid is a proton donor, while a base is a proton acceptor. Understanding this concept is crucial for determining the stability of bases, as it helps to identify which species can effectively accept protons in a given context.

Electronegativity

Electronegativity is a measure of an atom's ability to attract and hold onto electrons. In the context of bases, a more electronegative atom can stabilize the negative charge that results from proton acceptance. Comparing the electronegativities of nitrogen in ammonia (NH3) and oxygen in water (H2O) is essential for assessing their relative basicity and stability.

Resonance Stabilization

Resonance stabilization refers to the delocalization of electrons across multiple structures, which can enhance the stability of a molecule. In the case of bases, resonance can help distribute the negative charge more evenly, making the base more stable. Understanding how resonance applies to the conjugate acids of NH3 and H2O can provide insight into their relative stabilities as bases.

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Which is the most stable base in each pair?(c) NH3 vs. H2O

Key Concepts

Acid-Base Theory

Electronegativity

Resonance Stabilization

Watch next

Which is the most stable base in each pair?
(c) NH₃ vs. H₂O