Answer
64.8k+ views
Hint: Firstly, for comparison we should know under what category these compounds belong so that the comparison work becomes easier. Acetone and benzophenone come under ketones and benzaldehyde and acetaldehyde are compounds of the aldehyde group. Aldehydes contain a functional group with the structure$\text{-CHO}$, consisting of a carbon which is double-bonded to oxygen with the carbon atom bonded to hydrogen and other R groups which can be alkyl or side chain. Ketone is a functional group in organic chemistry containing a carbonyl group.
Complete step by step answer:
Let us move back to the question to discuss reactivity. Reactivity in case of aldehydes and ketones is decided by two factors: (1) Steric hindrance (2) Electrophilicity of carbon with oxygen
(1) Steric hindrance: It is the congestion created by presence of surrounding atoms or ligands which may slow down or even prevent reaction to occur. In Ketones, there is large hindrance caused by the bulky alkyl groups attached to$\text{C=O}$; due to which incoming nucleophiles do not have the required space to form bonds with carbon. This lowers the reactivity of ketones in large amounts than aldehydes.
![](https://www.vedantu.com/question-sets/d0f06016-7fb0-41f2-93da-27cb3711725d621932625308490184.png)
Due to the large and bulky size of the phenyl group, steric hindrance caused by benzaldehyde is more than acetaldehyde. Similarly, benzophenone has two phenyl groups present in its structure; the hindrance created by it is more than that created by methyl groups of acetone. That is why, acetaldehyde is more reactive than benzaldehyde and acetone is more reactive than benzophenone.
(2) Electrophilicity of carbonyl carbon: Due to electronegativity of oxygen the double-bonded carbon attached to it acquires partial positive charge, which makes the attack of nucleophiles easier. But the presence of electron donating groups nullifies the positive charge created. Thus, the presence of electron donating groups decreases the nucleophilic addition reaction.
Hence, the order of reactivity of all compounds is$\text{C}{{\text{H}}_{3}}\text{CHO}{{\text{C}}_{6}}{{\text{H}}_{5}}\text{CHOC}{{\text{H}}_{3}}\text{COC}{{\text{H}}_{3}}\text{}{{\text{C}}_{6}}{{\text{H}}_{5}}\text{CO}{{\text{C}}_{6}}{{\text{H}}_{5}}$. Thus, acetaldehyde is the most reactive compound which is option ‘d’.
Note: Do not mark benzaldehyde as the most reactive compound. As, benzaldehyde is stabilized by resonance effect,
![](https://www.vedantu.com/question-sets/961fffd5-0252-4266-8312-47f5dcf3f1076392140161687359638.png)
So, reactivity of benzaldehyde will not increase; apparently it will decrease because stability means potential energy to decrease and a compound reacts to lower its potential energy.
Complete step by step answer:
Let us move back to the question to discuss reactivity. Reactivity in case of aldehydes and ketones is decided by two factors: (1) Steric hindrance (2) Electrophilicity of carbon with oxygen
(1) Steric hindrance: It is the congestion created by presence of surrounding atoms or ligands which may slow down or even prevent reaction to occur. In Ketones, there is large hindrance caused by the bulky alkyl groups attached to$\text{C=O}$; due to which incoming nucleophiles do not have the required space to form bonds with carbon. This lowers the reactivity of ketones in large amounts than aldehydes.
![](https://www.vedantu.com/question-sets/d0f06016-7fb0-41f2-93da-27cb3711725d621932625308490184.png)
Due to the large and bulky size of the phenyl group, steric hindrance caused by benzaldehyde is more than acetaldehyde. Similarly, benzophenone has two phenyl groups present in its structure; the hindrance created by it is more than that created by methyl groups of acetone. That is why, acetaldehyde is more reactive than benzaldehyde and acetone is more reactive than benzophenone.
(2) Electrophilicity of carbonyl carbon: Due to electronegativity of oxygen the double-bonded carbon attached to it acquires partial positive charge, which makes the attack of nucleophiles easier. But the presence of electron donating groups nullifies the positive charge created. Thus, the presence of electron donating groups decreases the nucleophilic addition reaction.
Hence, the order of reactivity of all compounds is$\text{C}{{\text{H}}_{3}}\text{CHO}{{\text{C}}_{6}}{{\text{H}}_{5}}\text{CHOC}{{\text{H}}_{3}}\text{COC}{{\text{H}}_{3}}\text{}{{\text{C}}_{6}}{{\text{H}}_{5}}\text{CO}{{\text{C}}_{6}}{{\text{H}}_{5}}$. Thus, acetaldehyde is the most reactive compound which is option ‘d’.
Note: Do not mark benzaldehyde as the most reactive compound. As, benzaldehyde is stabilized by resonance effect,
![](https://www.vedantu.com/question-sets/961fffd5-0252-4266-8312-47f5dcf3f1076392140161687359638.png)
So, reactivity of benzaldehyde will not increase; apparently it will decrease because stability means potential energy to decrease and a compound reacts to lower its potential energy.
Recently Updated Pages
Write a composition in approximately 450 500 words class 10 english JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Arrange the sentences P Q R between S1 and S5 such class 10 english JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
What is the common property of the oxides CONO and class 10 chemistry JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
What happens when dilute hydrochloric acid is added class 10 chemistry JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
If four points A63B 35C4 2 and Dx3x are given in such class 10 maths JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
The area of square inscribed in a circle of diameter class 10 maths JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Other Pages
A boat takes 2 hours to go 8 km and come back to a class 11 physics JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
In the ground state an element has 13 electrons in class 11 chemistry JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Differentiate between homogeneous and heterogeneous class 12 chemistry JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Electric field due to uniformly charged sphere class 12 physics JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
According to classical free electron theory A There class 11 physics JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Excluding stoppages the speed of a bus is 54 kmph and class 11 maths JEE_Main
![arrow-right](/cdn/images/seo-templates/arrow-right.png)