Which is a stronger acid? c. <IMAGE> d. CH 3 CH 2 CH 2 OH or CH 3 CH 2 CH 2 SH

Hey everyone. And welcome back in today's video, we're going to identify the stronger asset in each pair. Starting with a, we can simply draw the two given structures were given ethanol. So let's draw that in a bond line representation and expand our oxygen hydrogen bond. And the second structure is ethyl amine, we are going to expand at nitrogen, hydrogen bond. In each case, we are going to define our civic hygiene, which is bonded to a more electro negative atom oxygen and nitrogen respectively. And whenever we are thinking about acidity, we have very similarly looking structures. But we have to generally consider two aspects a size and be electro negativity. In this case, because oxygen and negative the two atoms that have hydrogen bonded to them, they're in the same period of the periodic table. That means they have a comparable size. So we are not considering size in this case, meaning electro negativity should be the standpoint for us to use here. Oxygen is more electro negative than nitrogen is. And because oxygen is more electro negative, that means the O H bond it's more polarized since oxygen is electron withdrawing and the electron densities closer to oxygen than it is to nitrogen. Since nitrogen is less electro negative. And therefore, because the O H bond is more polarized, it implies that it is easier for us to break it. The more polarized our bond is the easier it is for us to break it. And the easier it is for us to release that hydrogen into solution in the form of an acidic proton. Meaning the first structure is a stronger asset, ethanol is more acidic than ethyl. I mean, similarly, if we look at B, we are going to draw the two structures, sees three, sees 20 H and then we have our second structure which is CH three CH two S H. So the main difference is that we are comparing O H versus S H. The question is which bond is easier to break? Do they have comparable size or not? Because if you look at the periodic table going down the group, you will notice that you get oxygen and after oxygen there's sulfur going down the group, the atomic radius increases, meaning sulfur is larger than oxygen. Since oxygen and sulfur do not belong to the same period, but they are in different periods. Size matters and not electro negativity since sulfur is a larger atom, that means there's a weaker attraction force between the nuclei of sulfur and hydrogen based on the Columbia claw of attraction. Remember that the greater the distance between the two atoms, the lower the attraction force between them. So, since sulfur is larger, that means the attraction force between sulfur and hygiene is lower and the bond as age is weaker, therefore, it is easier for us to release that hydrogen into solution in the form of a proton. While oxygen is smaller and the attraction force between auction and hodgins is greater, right? So if there's a greater force, it is harder for us to break that bond. Therefore, the second compound is a stronger asset. Okay. So we got our answers. And let's conclude everything for a compound number one is more acidic. Since oxygen and nitrogen, they have comparable sizes, but oxygen is more electro negative. And for B compound two is more acidic because between sulfur and oxygen, sulfur has bigger size, they do not belong to the same period based on these answers, we may conclude that the correct answer to the multiple choice question is c 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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5:14 minutes

Problem 27c,d

Textbook Question

Which is a stronger acid?
c. <IMAGE>
d. CH₃CH₂CH₂OH or CH₃CH₂CH₂SH

Verified step by step guidance

Step 1: Understand the concept of acidity. Acidity is determined by the ability of a molecule to donate a proton (H⁺). The strength of an acid is influenced by factors such as electronegativity, bond strength, and the stability of the conjugate base formed after losing a proton.

Step 2: Compare the electronegativity of the atoms bonded to hydrogen in the functional groups. Oxygen (in CH3CH2CH2OH) is more electronegative than sulfur (in CH3CH2CH2SH), meaning it can better stabilize the negative charge on the conjugate base after losing a proton.

Step 3: Consider the bond strength between hydrogen and the atom it is attached to. The O-H bond in CH3CH2CH2OH is stronger than the S-H bond in CH3CH2CH2SH, making it harder for CH3CH2CH2OH to lose a proton compared to CH3CH2CH2SH.

Step 4: Evaluate the stability of the conjugate base. After losing a proton, the conjugate base of CH3CH2CH2OH (CH3CH2CH2O⁻) is less stable than the conjugate base of CH3CH2CH2SH (CH3CH2CH2S⁻) because sulfur can better accommodate the negative charge due to its larger atomic size.

Step 5: Based on the above factors, CH3CH2CH2SH is the stronger acid compared to CH3CH2CH2OH because sulfur's lower electronegativity and larger atomic size allow for better stabilization of the conjugate base, making it easier to donate a proton.

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Key Concepts

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

Acidity and pKa

Acidity refers to the ability of a compound to donate a proton (H+). The strength of an acid is often measured by its pKa value; lower pKa values indicate stronger acids. Understanding the relationship between pKa and acid strength is crucial for comparing different compounds.

Alcohols vs. Thiols

Alcohols (R-OH) and thiols (R-SH) are both functional groups containing a hydroxyl or sulfhydryl group, respectively. Thiols are generally more acidic than alcohols due to the weaker S-H bond compared to the O-H bond, which makes it easier for thiols to release a proton.

Inductive Effect

The inductive effect refers to the electron-withdrawing or electron-donating effects of substituents on the acidity of a compound. Electronegative atoms or groups can stabilize the negative charge of the conjugate base formed after deprotonation, thereby increasing acidity. This concept is important when comparing the acidity of different organic compounds.

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