Identify the most and the least acidic compound in each of the following sets. a. 2-chlorobutanoic acid: 4-chlorobutanoic acid: 3-chlorobutanoic acid:.
b. 2,4-dinitrobenzoic acid: p-nitrobenzoic acid: p-bromobenzoic acid:.
c. p-cyanobenzoic acid: benzoic acid: p-aminobenzoic acid:.

See explanation

Explanation:

Our answer options for this question are:

a. 2-chlorobutanoic acid:_______ 2-chlorobutanoic acid:_______ 3-chlorobutanoic acid:______.

b. 2,4-dinitrobenzoic acid:______ p-nitrobenzoic acid:______ p-bromobenzoic acid:_______.

c. p-cyanobenzoic acid:________ benzoic acid:_______ p-aminobenzoic acid:______

We have to check each set of molecules

a. 2-chlorobutanoic acid, 3-chlorobutanoic acid

In this case, the difference between these molecules is the position of "Cl". If the chlorine atom is closer to the acid group, we will have a higher inductive effect. So, the bond O-H would be weaker and we will have more acidity. So, the molecule with more acidity is 2-chlorobutanoic acid and the less acidic would be 3-chlorobutanoic acid.

b. 2,4-dinitrobenzoic acid, p-nitrobenzoic acid, p-bromobenzoic acid

In this case, we have several structural differences. In all the structure, we have deactivating groups ( and ). If we have a deactivating group the acidity will increase. In the case of "Br", we have a weak deactivating, so, this will be the less acidic one (p-bromobenzoic acid)

in 2,4-dinitrobenzoic acid we have two deactivating groups, therefore, this would be the most acid compound.

c. p-cyanobenzoic acid, benzoic acid, p-aminobenzoic acid

On these molecules, we have several structural differences. In p-cyanobenzoic acid we have a deactivating group, therefore in this molecule we will have more acidity. In the p-aminobenzoic acid, we have an activating group, so, this would be the less acidic compound.

See figure 1

I hope it helps!

fe 55.85 g/mol and h2o 18.02 g/mol.