What is the conjugate base of each of the following? 1. NH 3 2. HBr 3. HNO 3 4. H 2 O

Hello, everyone. Let's do this problem. It says write the conjugate base for the below given species. Part A hydrogen iodide, part B, sulfuric acid, part C, methanol and part D nitrous acid. So notice these are all acids and we want to write the conjugate basis. So how do we convert an acid to a conjugate base? Well, according to the Bronte Lowry acid based theory, when an acid loses a proton, it forms the conjugate base. So I'm going to write the dissociation reactions for each of these acids to show them producing the conjugate base and a proton. So for part A, we have hydrogen iodide H I dissociating into I minus and H plus. So notice the acid is neutral, which means when it loses the proton, the conjugate base will be negatively charged. Part B, we have sulfuric acid which is H two S dissociating to HS 04 and H plus part C, we have methanol which is C H 30 H losing a proton. It'll dissociate into C H 30 minus and H plus. Lastly part D, we have nitrous acid which is H N dissociates N 2 N and H plus. So let me list out all the conjugate bases for each one of these parts. Part A we have I minus part B H S 04 minus, part C C H 30 minus and part D N minus. So those are the conjugate bases for all of these acids, which makes a, the correct answer for this problem. That's it for this one. I hope this video is helpful and 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

Acids and Bases

Organic Chemistry

3. Acids and Bases

Acids and Bases

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2:39 minutes

Problem 4b

Textbook Question

What is the conjugate base of each of the following?
1. NH₃
2. HBr
3. HNO₃
4. H₂O

Verified step by step guidance

Step 1: Understand the concept of a conjugate base. A conjugate base is formed when an acid donates a proton (H⁺). The conjugate base will have one less hydrogen atom and a negative charge compared to the original acid.

Step 2: For NH₃ (ammonia), identify the acid and remove one proton (H⁺). The conjugate base will be NH₂⁻. This is because NH₃ loses a hydrogen atom and gains a negative charge.

Step 3: For HBr (hydrobromic acid), remove one proton (H⁺) from the molecule. The conjugate base will be Br⁻, as HBr loses its hydrogen atom and becomes negatively charged.

Step 4: For HNO₃ (nitric acid), remove one proton (H⁺) from the molecule. The conjugate base will be NO₃⁻, as HNO₃ loses its hydrogen atom and gains a negative charge.

Step 5: For H₂O (water), remove one proton (H⁺) from the molecule. The conjugate base will be OH⁻, as H₂O loses a hydrogen atom and becomes negatively charged.

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Key Concepts

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

Conjugate Acid-Base Theory

The conjugate acid-base theory, developed by Brønsted and Lowry, defines acids as proton donors and bases as proton acceptors. When an acid donates a proton (H+), it forms its conjugate base, while the base that accepts the proton becomes its conjugate acid. Understanding this relationship is crucial for identifying conjugate pairs in chemical reactions.

Ammonia (NH3) and its Conjugate Base

Ammonia (NH3) acts as a weak base in aqueous solutions. When it accepts a proton, it forms its conjugate acid, ammonium (NH4+). The conjugate base of ammonia, however, is the amide ion (NH2-), which is formed when ammonia donates a proton. Recognizing this transformation is essential for solving the question.

Strong Acids and Their Conjugate Bases

Strong acids, such as HBr and HNO3, completely dissociate in water, meaning they donate protons readily. The conjugate bases of strong acids are typically very weak and have negligible basicity. For example, the conjugate base of HBr is bromide ion (Br-), and for HNO3, it is nitrate ion (NO3-). Understanding the strength of acids and their corresponding conjugate bases is vital for this question.

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