Strongest Acid among the Given Compounds

There are four compounds given in the question, and we have to find the strongest acid among them. To determine the strength of an acid, we need to look at its dissociation constant (Ka) value. The higher the Ka value, the stronger the acid.

Dissociation Constant (Ka) and Strength of Acid

Dissociation constant (Ka) is an equilibrium constant that measures the degree of dissociation of an acid in an aqueous solution. In simpler terms, it is a measure of the strength of an acid. The dissociation constant is given by the equation:

HA + H2O ⇌ H3O+ + A-

Ka = [H3O+][A-]/[HA]

where HA is the acid, A- is the conjugate base of the acid, H3O+ is the hydronium ion, and [ ] represents the concentration in moles per liter.

Calculating Ka Values for the Given Compounds

1. CH3COOH (Acetic Acid)

Ka = 1.8 x 10^-5

2. C6H5COOH (Benzoic Acid)

Ka = 6.5 x 10^-5

3. m-CH3-O-C6H4COOH (3-Methoxybenzoic Acid)

Ka = 3.7 x 10^-5

4. p-CH3-O-C6H4-COOH (4-Methoxybenzoic Acid)

Ka = 3.5 x 10^-5

Analysis of Ka Values

From the above calculations, we can see that the Ka value of benzoic acid (C6H5COOH) is the highest among the given compounds. This means that benzoic acid is the strongest acid among the given compounds.

Conclusion

In conclusion, the strongest acid among the given compounds is benzoic acid (C6H5COOH) with a Ka value of 6.5 x 10^-5.

Benezoic acid