Question

Write the structural formulas of all the esters that can be formed by ethylene glycol with formic and acetic acids. (One or both of the \(-\) OH groups of ethylene glycol can react.)

Short answer

Answer: The possible esters formed are: 1. HCOO-CH2-CH2-OH 2. HO-CH2-CH2-OC(O)H 3. CH3COO-CH2-CH2-OH 4. HO-CH2-CH2-OC(O)CH3 5. HCOO-CH2-CH2-OC(O)H 6. CH3COO-CH2-CH2-OC(O)CH3

Step-by-step solution

Ethylene glycol with one formic acid

In this step, one of the OH groups of ethylene glycol reacts with formic acid. This reaction results in two different esters with one ester group (HCOO) attached to either end of ethylene glycol. Ester 1: \(-\) OCH_2CH_2OH + HCOOH \(-\) OCH_2CH_2OC(O)H + H_2O Ester 1 structure: HCOO-CH2-CH2-OH Ester 2: HOCH_2CH_2O \(-\) + HCOOH \(-\) HOCH_2CH_2OC(O)H + H_2O Ester 2 structure: HO-CH_2-CH_2-OC(O)H

Ethylene glycol with one acetic acid

In this step, one of the OH groups of ethylene glycol reacts with acetic acid. This reaction results in two different esters with one ester group (CH3COO) attached to either end of ethylene glycol. Ester 3: \(-\) OCH_2CH_2OH + CH3COOH \(-\) OCH_2CH_2OC(O)CH3 + H_2O Ester 3 structure: CH3COO-CH2-CH2-OH Ester 4: HOCH_2CH_2O \(-\) + CH3COOH \(-\) HOCH_2CH_2OC(O)CH3 + H_2O Ester 4 structure: HO-CH2-CH2-OC(O)CH3

Ethylene glycol with one formic and one acetic acid

In this step, both of the OH groups of ethylene glycol react, one with formic acid and the other with acetic acid. This reaction forms a mixed ester. Mixed Ester: \(-\) OCH2CH2O \(-\) + HCOOH + CH3COOH \(-\) OCH_2CH_2OC(O)CH3 + HCOOCH_2CH_2OC(O)H + 2 H_2O Mixed Ester structure: HCOO-CH2-CH2-OC(O)CH3

Ethylene glycol with two formic acids

In this step, both of the OH groups of ethylene glycol react with formic acid, resulting in an ester with two HCOO groups. Ester 5: \(-\) OCH_2CH_2O \(-\) + 2 HCOOH \(-\) HCOOCH_2CH_2OC(O)H + 2 H_2O Ester 5 structure: HCOO-CH2-CH2-OC(O)H

Ethylene glycol with two acetic acids

In this step, both of the OH groups of ethylene glycol react with acetic acid, resulting in an ester with two CH3COO groups. Ester 6: \(-\) OCH_2CH_2O-\( + 2 CH3COOH \)-$ CH3COOCH_2CH_2OC(O)CH3 + 2 H_2O Ester 6 structure: CH3COO-CH2-CH2-OC(O)CH3 In conclusion, the following esters can be formed by ethylene glycol with formic and acetic acids: 1. HCOO-CH2-CH2-OH 2. HO-CH2-CH2-OC(O)H 3. CH3COO-CH2-CH2-OH 4. HO-CH2-CH2-OC(O)CH3 5. HCOO-CH2-CH2-OC(O)H 6. CH3COO-CH2-CH2-OC(O)CH3