Arrange in the increasing order of Acid strength ---- CCL3.COOH, CH3COOH, CHCL2.COOH

To arrange the acids CCl3COOH, CH3COOH, and CHCl2COOH in order of increasing acid strength, we need to consider the effects of the substituents on the carboxylic acid group (-COOH). The strength of an acid is influenced by its ability to donate a proton (H+) and the stability of the resulting anion after deprotonation.

Understanding Acid Strength

Acid strength is often determined by two main factors: the stability of the conjugate base and the electronegativity of substituents attached to the carbon chain. In carboxylic acids, substituents that are more electronegative can stabilize the negative charge on the conjugate base through inductive effects, making the acid stronger.

Analyzing Each Acid

• CCl3COOH (Trichloroacetic acid): The three chlorine atoms are highly electronegative and exert a strong -I (inductive) effect, pulling electron density away from the carboxylate ion (the conjugate base). This stabilization makes CCl3COOH a very strong acid.
• CHCl2COOH (Dichloroacetic acid): This acid has two chlorine atoms. While it is still strong due to the -I effect, it is less effective than CCl3COOH because it has one less electronegative chlorine to stabilize the conjugate base.
• CH3COOH (Acetic acid): The methyl group (-CH3) is electron-donating through a +I (inductive) effect, which destabilizes the conjugate base compared to the chlorinated acids. Therefore, acetic acid is the weakest of the three.

Arranging the Acids

Based on the analysis of the inductive effects of the substituents, we can arrange the acids in order of increasing strength:

• CH3COOH (weakest)
• CHCl2COOH
• CCl3COOH (strongest)

Final Thoughts

In summary, the order of increasing acid strength is CH3COOH < CHCl2COOH < CCl3COOH. The presence of electronegative chlorine atoms significantly enhances the acidity of the compounds by stabilizing the conjugate base, while the methyl group in acetic acid reduces its acidity. Understanding these concepts helps in predicting the behavior of various acids based on their molecular structure.