Question

Rank each set of compounds in order of increasing acidity: 2,4-Dichlorobutyric acid 2,3-Dichlorobutyric acid 3,4-Dimethylbutyric acid 2,4-dichlorobutyric acid is the most acidic and 3,4-dimethylbutyric acid is the least acidic. 2,4-dichlorobutyric acid is the most acidic and 2,3-dimethylbutyric acid is the least acidic. 3,4-dimethylbutyric acid is the most 2,3-dichlorobutyric acidic and acid is the least acidic. 2,3-dichlorobutyric acid is the most acidic and 3,4-dimethylbutyric acid is the least acidic. SHOW HINT 3-Bromopropionic acid 2,2-Dibromopropionic acid 3,3-Dibromopropionic acid 2,2-dibromopropionic acid is the most acidic and 3,3-bromopropionic acid is the least acidic. 3,3-dibromopropionic acid is the most acidic and 3-bromopropionic acid is the least acidic. 2,2-dibromopropionic acid is the most acidic and 3-bromopropionic acid is the least acidic. 3-dibromopropionic acid is the most acidic and 3,3-bromopropionic acid is the least acidic.

Answer 1

To determine increasing acidity, halogens increase acidity through inductive effects, while alkyl groups decrease it. Therefore, 2,4-Dichlorobutyric acid is the most acidic, and 3,4-Dimethylbutyric acid is the least acidic in the first set. In the second set, 2,2-Dibromopropionic acid is the most acidic, while 3-Bromopropionic acid is the least.

Step-by-step explanation:

To rank these compounds in order of increasing acidity, we need to consider the effects of substituents on the acidity of the carboxylic acid. Halogens, such as chlorine, have an electron-withdrawing effect and increase acidity through inductive effects, whereas alkyl groups like methyl are electron-donating and decrease acidity.

For the first set:

• 3,4-Dimethylbutyric acid is the least acidic due to electron-donating methyl groups.
• 2,3-Dichlorobutyric acid follows, with the chlorines close to the carboxyl group, which increases acidity, but not as much as in 2,4-dichlorobutyric acid.
• 2,4-Dichlorobutyric acid is the most acidic due to two chlorine atoms being positioned to exert strong inductive electron-withdrawing effects, stabilizing the carboxylate anion.

For the second set:

• 3-Bromopropionic acid has the least acidity since the bromine is only moderately withdrawing and is further from the carboxyl group.
• 3,3-Dibromopropionic acid is next; despite two bromines, its increased acidity is due to symmetrical substitution, which somewhat stabilizes the anion.
• 2,2-Dibromopropionic acid is the most acidic because the two strongly electron-withdrawing bromines are adjacent to the carboxyl group, greatly stabilizing the anion formed.

Therefore, the correct order for the first set is: 3,4-Dimethylbutyric acid < 2,3-Dichlorobutyric acid < 2,4-Dichlorobutyric acid. And for the second set: 3-Bromopropionic acid < 3,3-Dibromopropionic acid < 2,2-Dibromopropionic acid.

Answer 2

In the first question;

Option D is correct answer i.e 2,3-dichlorobutyric acid is the most acidic and 3,4-dimethylbutyric acid is the least acidic.

In the second question;

Option A is the correct answer , 2,2-dibromopropionic acid is the most acidic and 3,3-bromopropionic acid is the least acidic.

Step-by-step explanation:

The rate of acidity of carboxylic acid is affect by several factors.

For example;

Inductive effect is used to explain the acidity of carboxylic acids.

Acidity of carboxylic acid increase by withdrawing group (NO2,CN,X,ROH) and decreases by donating groups (OMe,NH2,alkyl group).

Halogen family group are highly electronegative and as such they increases the rate of acidity.

Also in naming organic compounds, we rank compounds with the least number of substituent attached to the organic compound.

In the first question, Option D is correct answer i.e 2,3-dichlorobutyric acid is the most acidic and 3,4-dimethylbutyric acid is the least acidic because 2,3-dichlorobutyric acid have the least number of substituent of chlorine atoms and chlorine atoms as well increases the rate of acidity.

Also, 3,4-dimethylbutyric acid is the least acidic because of attachment of methyl groups and higher number of substituent(methyl groups) attached to it.

In the second question:

Option A is the correct answer , 2,2-dibromopropionic acid is the most acidic and 3,3-bromopropionic acid is the least acidic because

Bromine (an halogen family atom) increase the rate of acidity and with decreasing the distance from COOH group, acidity increases. Also with increasing the distance from COOH group acidity decreases which makes Option A the correct answer.