Tag: functional derivatives of carboxylic acids

Questions Related to functional derivatives of carboxylic acids

Which of the following is not a derivative of carboxylic acids ?

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. anhydrides

  2. esters

  3. amines

  4. amides

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Correct Option: C
Explanation:

C
Rest all are derivatives of carboxylic acids.And directly by the hydrolysis of amines carboxylic acids cannot be formed.

Which of the following cannot be named as a derivative of $CH _{3}COOH$?

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. $CH _{3}CH _{2}COOH$

  2. $(CH _{3}) _{2}CHCOOH$

  3. $HCOOH$

  4. $(CH _{3}) _{3}CCOOH$

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Correct Option: C
Explanation:

Option A, B and D can be derived from $CH _3 COOH$ while option C, i.e., $HCOOH$ cannot be derived from $CH _3COOH$ as $HCOOH$ has one carbon less than $CH _3COOH$.


Option C is correct.

Which of the following statements is wrong?

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. For the synthesis of esters from carboxylic acids and alcohols, we can often use a base as a catalyst.

  2. For the synthesis of esters from carboxylic acids and alcohols, we can often use an additional acid as a catalyst.

  3. For the alkaline hydrolysis of carboxylic esters, we need to use an excess of base.

  4. For the hydrolysis of carboxylic esters under acidic conditions, we need only a catalytic amount of an additional acid.

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Correct Option: A

With which of the following can ethyl ethanoate not undergo a substitution reaction?

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. $CH _3CO _2Na$

  2. aqueous $NaOH$

  3. $CH _3OH$, $H^+$

  4. aqueous $NH _3$

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Correct Option: A

Amides and acid chlorides are:

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. organic functional group

  2. functional derivative of carboxylic acid

  3. both $A$ and $B$

  4. none of these

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Correct Option: C
Explanation:

Amides and Acid chlorides are organic Functional group and functional derivative of carboxylic acid. Amide has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - NH _2  $. Carboxylic acid has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - OH  $. An example of amide is acetamide $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - NH _2   $. An example of carboxylic acid is acetic acid $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - OH  $. Acid chloride has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - Cl  $.  An example of acid chloride is acetyl chloride $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - Cl  $. 

As the molecular weight increases the boiling point of carboxylic acid:

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. increases

  2. decreases

  3. remain same

  4. none of the above

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Correct Option: A
Explanation:

As the molecular weight increases the boiling point of carboxylic acid increases. Lower aliphatic carboxylic acids (upto 9 C atoms) are liquids, the higher members are wax like solids.

Identify the main functional derivative of carboxylic acid.

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. Ester

  2. Alkane

  3. Alcohol

  4. None of these

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Correct Option: A
Explanation:

Ester is the main functional derivative of carboxylic acid. Ester has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - OR'  $. Carboxylic acid has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - OH  $. An example of ester is ethyl acetate $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - O-CH _2-CH _3  $. An example of carboxylic acid is acetic acid $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - OH  $

Which of the following is acyl halide?

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. $R-CO-X$

  2. $R-CO-O-CO-O-R$

  3. $R-COOH$

  4. $R-CO-NH _2$

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Correct Option: A
Explanation:

Acyl halide is $R-CO-X$
Hence option A is correct.

Identify the functional derivative of carboxylic acid.
$CH _3-CO-O-CO-CH _3$

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. Amide

  2. Ester

  3. Acyl halides

  4. Acid anhydride

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Correct Option: D
Explanation:

An acid hydride is a compound that has two acyl groups $(CH _{3}COO)$ bonded to the same oxygen atom

Acyl halide and acid halide are same groups.

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. True

  2. False

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Correct Option: A
Explanation:

The given statement is True.
Acyl halide and acid halide are same groups. They represent the function group
  $\displaystyle R- \underset {\displaystyle  \underset {\displaystyle \text {O }}{||} }{C}-X$  where X is halogen atom (F, Cl, Br or I). They are derived from carboxylic acids (  $\displaystyle R- \underset {\displaystyle  \underset {\displaystyle \text {O }}{||} }{C}-OH$ ) by replacing a hydroxyl group (-OH) with a halide group.
An example is acetyl chloride  $\displaystyle CH _3- \underset {\displaystyle  \underset {\displaystyle \text {O }}{||} }{C}-Cl$
Another example is benzoyl chloride $\displaystyle Ph- \underset {\displaystyle  \underset {\displaystyle \text {O }}{||} }{C}-Cl$