Rank the following compounds from strongest to weakest acid:CH3CH2OH; CH3CH2NH2; CH3CH2SH; CH3CH2CH3

Ch. 2 - Acids and Bases: Central to Understanding Organic Chemistry

Bruice8th EditionOrganic ChemistryISBN: 9780135213711당신이 사용하는 게 아니라요?교과서 변경

모든 교과서

Bruice 8th Edition

Ch. 2 - Acids and Bases: Central to Understanding Organic Chemistry

문제 59

2장, 문제 59

Rank the following compounds from strongest to weakest acid:
CH₃CH₂OH; CH₃CH₂NH₂; CH₃CH₂SH; CH₃CH₂CH₃

검증된 단계별 안내

Step 1: Understand the concept of acidity. Acidity is determined by the ability of a compound to donate a proton (H⁺). The more stable the conjugate base after losing a proton, the stronger the acid.

Step 2: Analyze the functional groups in each compound. CH3CH2OH contains an alcohol (-OH) group, CH3CH2NH2 contains an amine (-NH2) group, CH3CH2SH contains a thiol (-SH) group, and CH3CH2CH3 is an alkane with no acidic functional group.

Step 3: Compare the electronegativity of the atoms directly bonded to hydrogen in each functional group. Oxygen in CH3CH2OH is more electronegative than sulfur in CH3CH2SH, and sulfur is more electronegative than nitrogen in CH3CH2NH2. Electronegativity affects the stability of the conjugate base.

Step 4: Consider the polarizability of the atoms. Sulfur in CH3CH2SH is larger and more polarizable than oxygen in CH3CH2OH, which can stabilize the conjugate base better, making thiols generally more acidic than alcohols.

Step 5: Evaluate CH3CH2CH3. Alkanes like CH3CH2CH3 lack acidic functional groups and are extremely weak acids. Rank the compounds based on the above analysis: CH3CH2SH > CH3CH2OH > CH3CH2NH2 > CH3CH2CH3.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

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 structure and acidity is crucial, as factors like electronegativity and resonance can influence a compound's ability to stabilize the negative charge of its conjugate base.

Functional Groups and Their Effects

Different functional groups have varying effects on acidity. For example, alcohols (like CH3CH2OH) can donate protons due to the hydroxyl (-OH) group, while amines (like CH3CH2NH2) are generally basic and less acidic. Thiols (like CH3CH2SH) are more acidic than alcohols due to the lower electronegativity of sulfur compared to oxygen, which stabilizes the conjugate base.

Inductive Effect and Hybridization

The inductive effect refers to the electron-withdrawing or electron-donating effects of substituents on acidity. Electronegative atoms can stabilize the negative charge of a conjugate base, enhancing acidity. Additionally, the hybridization of the atom bearing the acidic proton affects acidity; sp-hybridized carbons are more acidic than sp2 or sp3 due to increased s-character, which holds the electrons closer to the nucleus.