Question

The ascending acidity order of the following H atoms is

• A. $C < D < B < A$
• B. $ A < B < C < D $
• C. $ A < B < D < C$
• D. $D < C < B < A$

Answer 1

The Correct Option is A

To determine the acidity order of the given hydrogen atoms, we need to consider the stability of the conjugate base formed after hydrogen removal. Acidity is directly related to the stability of the conjugate base; more stable conjugate bases mean higher acidity. 

1. In structure A, hydrogen is attached to an sp-hybridized carbon. The conjugate base, formed after losing this hydrogen, is stabilized by the high s-character, making it the most acidic.
2. In structure B, hydrogen is attached to an sp²-hybridized carbon. The stability of its conjugate base is less than that of sp-hybridized carbon but greater than sp³.
3. In structure C, hydrogen is attached to an sp³-hybridized carbon, making it the least acidic as the conjugate base is least stabilized.
4. In structure D, hydrogen is attached to another sp³-hybridized carbon, but the surrounding groups and structural context offer slightly better stability than C, making it more acidic than C.

Based on the above reasoning, the correct order of acidity is \(C < D < B < A\).

Answer 2

The given compounds are:

The acidity strength is governed by the stability of the conjugate base. The more stable the conjugate base, the stronger the acid.

Stability of conjugate base α acidic strength

The order of acidity, based on the structure and conjugate base stability, is:

C < D < B < A
Thus, the ascending order of acidity is C < D < B < A.
The Correct Answer is : C < D < B < A