Acidity of Carboxylic Acid

Simple wording prepared by Ali Zia

1. Topic Acidity Of Carboxylic Acid

2. Presented By Ali Zia

3. Presented To Mam Samman Arshad

4. Table Of Contents Acidity Of Carboxylic Acid Acidity Constant Effects of Substituent on acidity of Carboxylic Acid

5. Acidity Of Carboxylic Acid The distinctive chemical feature of the carboxylic acids is their acidity which merits a detailed discussion. In an aqueous solution, molecules of these acids interact with water molecules to form carboxylate ions and hydronium ions.

6. Acidity Of Carboxylic Acid

7. Acidity Of Carboxylic Acid As indicated above, most simple carboxylic acids are only slightly ionized in water and these are fairly weak acids. A 1 molar solution of acetic acid is ionized only to about 05% at room temperature white a strong acid like hydrochloric acid or sulphuric acid is almost completely ionized.

8. Acidity Of Carboxylic Acid Evidently water molecules are not very strong proton acceptors in relation to carboxylic acids, which are relatively weak proton donors.

9. Acidity Constant The ionization or dissociation equilibrium of a carboxylic acid, similar to inorganic acids, may be simply written as

10. Acidity Constant Where H+ represents a hydronium ion H 3 O. Applying the Mass Law, the dissociation constant or acidity constant K, for the above equilibrium can be expressed as

11. Acidity Constant The value of K. which is directly proportional to the concentration of hydrogen ions, is thus a measure of acidity of the individual acid under consideration. The larger the value of K. the greater the concentration of H ions and stronger the acid.

12. Acidity Constant For example the value of K. for acetic acid is 1'8 x lO while that for HCI is 10. Thus acetic acid is a much weaker acid than hydrochloric acid. The value of K. for ethyl alcohol is lO which has far low acidity compared to even acetic acid.

13. Refrences Courtesy by the book of Organic Chemistry