Q9. Arrange the following in the decreasing order of basic strength in aqueous solution:
(A) CH₃NH₂

Q: What is the correct answer for CUET UG Chemistry Q9?

The correct answer is b. The basic strength of amines in aqueous solution is determined by a combination of factors:1. **Inductive effect (+I effect):** Alkyl groups are electron-donating (+I effect). They increase the electron density on the nitrogen atom, making the lone pair more available for donation and thus increasing basicity. More alkyl groups generally mean stronger basicity.2. **Steric hindrance:** Bulky alky

Q: Q9. Arrange the following in the decreasing order of basic strength in aqueous solution: (A) CH₃NH₂ (B) (CH₃)₃N (C) (CH₃)₂NH (D) NH₃ (E) C₆H₅NH₂ Choose the correct answer from the options given below:

The correct answer is b. The basic strength of amines in aqueous solution is determined by a combination of factors:1. **Inductive effect (+I effect):** Alkyl groups are electron-donating (+I effect). They increase the electron density on the nitrogen atom, making the lone pair more available for donation and thus increasing basicity. More alkyl groups generally mean stronger basicity.2. **Steric hindrance:** Bulky alky

Q: What are the options for this CUET UG Chemistry question?

A. (C) (A) > (B) > (D) > (E) · C. (C) = (A) > (B) > (D) > (E) · D. (C) > (A) = (B) > (D) > (E)

Question

Q9. Arrange the following in the decreasing order of basic strength in aqueous solution:
(A) CH₃NH₂
(B) (CH₃)₃N
(C) (CH₃)₂NH
(D) NH₃
(E) C₆H₅NH₂
Choose the correct answer from the options given below:

FirstInTest · Accepted Answer

The basic strength of amines in aqueous solution is determined by a combination of factors:1.  **Inductive effect (+I effect):** Alkyl groups are electron-donating (+I effect). They increase the electron density on the nitrogen atom, making the lone pair more available for donation and thus increasing basicity. More alkyl groups generally mean stronger basicity.2.  **Steric hindrance:** Bulky alkyl groups can hinder the approach of a proton, reducing basicity.3.  **Solvation effect:** The stability of the protonated amine (conjugate acid) in aqueous solution depends on its solvation by water molecules. More hydrogen bonding with water molecules leads to greater stability and thus stronger basicity.For methyl-substituted amines in aqueous solution, the observed order is generally:Secondary amine > Primary amine > Tertiary amine > Ammonia.Let's analyze the given compounds:(A) CH₃NH₂ (Methylamine): Primary amine. Has one +I group (CH₃) and can form extensive H-bonds with water.(B) (CH₃)₃N (Trimethylamine): Tertiary amine. Has three +I groups, but experiences significant steric hindrance and forms fewer H-bonds (only one) with water, reducing its basicity compared to primary and secondary methylamines.(C) (CH₃)₂NH (Dimethylamine): Secondary amine. Has two +I groups (CH₃) and forms good H-bonds (two) with water. It offers the best balance of inductive effect and solvation, making it the strongest base among methylamines.(D) NH₃ (Ammonia): No +I groups. Basic due to the lone pair on nitrogen, but less basic than aliphatic amines.(E) C₆H₅NH₂ (Aniline): Aromatic amine. The lone pair of electrons on the nitrogen atom is delocalized into the benzene ring through resonance. This reduces the availability of the lone pair for protonation, making aniline significantly less basic than ammonia and aliphatic amines.Order of basic strength:C₆H₅NH₂ (E) is the least basic.NH₃ (D) is more basic than aniline.Among methylamines, (C) > (A) > (B).So the overall decreasing order of basic strength in aqueous solution is: (C) > (A) > (B) > (D) > (E).This matches option (b).

Answer

(C) < (A) < (B) < (D) < (E)

Answer

(C) > (A) > (B) > (D) > (E)

Answer

(C) = (A) > (B) > (D) > (E)

Answer

(C) > (A) = (B) > (D) > (E)

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