Question

Statement-1 : Benzene and ethene both give reactions with electrophilic reagents. Statement-2: Benzene and ethene both have loosely bound \(\pi\) electrons, which can be donated to vacant orbital of the electrophile. (1) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement- 1 . (2) Statement-1 is True, Statement- 2 is True; Statement-2 is NOT a correct explanation for Statement-1. (3) Statement-1 is True, Statement-2 is False. (4) Statement- 1 is False, Statement-2 is True.

Short answer

(1) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1.

Step-by-step solution

Analyze Statement-1

Examine if benzene and ethene can both react with electrophilic reagents. Benzene undergoes electrophilic aromatic substitution, and ethene undergoes electrophilic addition reactions. Thus, Statement-1 is True.

Analyze Statement-2

Check if benzene and ethene both have loosely bound \(\pi\) electrons that can be donated to the vacant orbital of an electrophile. Both benzene and ethene have \(\pi\) electrons which are loosely bound and available for reaction with electrophiles. Therefore, Statement-2 is also True.

Determine Correct Explanation

Determine if the loosely bound \(\pi\) electrons (Statement-2) explain why benzene and ethene react with electrophilic reagents (Statement-1). Since the availability of loosely bound \(\pi\) electrons enables these reactions, Statement-2 is indeed a correct explanation for Statement-1.

Key concepts

Benzene Chemistry

Benzene is a unique molecule in organic chemistry because of its stability and aromaticity. It is made up of six carbon atoms arranged in a hexagonal ring. Each carbon atom is bonded to one hydrogen atom, and they all share a set of three double bonds. These double bonds are delocalized, forming a cloud of \(\backslashpi\) electrons above and below the ring. This delocalization contributes to benzene's stability.
Benzene undergoes electrophilic aromatic substitution reactions. This is a type of reaction where an electrophile replaces a hydrogen atom in the benzene ring. The reason benzene can participate in these reactions is because of the availability of its loosely bound \(\backslashpi\) electrons. These electrons can be donated to electrophiles, which are species that seek electrons. This makes the benzene ring highly reactive towards electrophiles.
Some common electrophiles that react with benzene include halogens, nitronium ions, and sulfonium ions. These reactions are part of the versatility of benzene in synthetic chemistry, allowing for the creation of a wide range of derivatives.

Ethene Reactions

Ethene, also known as ethylene, is a simple hydrocarbon with the formula C2H4. It consists of two carbon atoms double-bonded to each other and each carbon has two hydrogen atoms. The double bond in ethene consists of one sigma bond and one \( \backslashpi \) bond.
Ethene undergoes electrophilic addition reactions. This type of reaction is characterized by the addition of an electrophile to the double bond of ethene. The \( \backslashpi \) electrons in the double bond are loosely held, making them available for reaction with electrophiles.
In these reactions, the \( \backslashpi \) bond is broken, and new sigma bonds are formed. For example, when ethene reacts with bromine, a bromonium ion is formed initially, which is then attacked by a bromide ion, resulting in 1,2-dibromoethane. These reactions are significant in organic synthesis and help in understanding more complex mechanisms.
Understanding ethene reactions is crucial for grasping the basics of organic chemistry. They not only show how \( \backslashpi \) electrons can interact with electrophiles but also lay the groundwork for studying more complicated molecules and reactions.

Pi Electrons

\( \backslashpi \) electrons are a key concept in understanding both benzene and ethene reactions. They are found in double bonds and aromatic systems and are characterized by their delocalized nature in the case of benzene, or their relatively weak binding in alkenes like ethene.
The term \( \backslashpi \) electrons refers to electrons in a \( \backslashpi \) orbital, which is formed by the side-to-side overlap of p orbitals. In benzene, the \( \backslashpi \) electrons are delocalized over the entire ring structure, giving it extra stability and making it less reactive than alkenes in certain situations. However, this delocalization allows for the specialized electrophilic aromatic substitution reactions.
In ethene, the \( \backslashpi \) electrons are localized within the double bond and are available to react with electrophiles. The localized nature of these \( \backslashpi \) electrons in ethene allows for the electrophilic addition reactions that are characteristic of alkenes.
In summary, \( \backslashpi \) electrons play a vital role in the reactivity of organic molecules. Their ability to interact with electrophiles underpins a range of reactions that are crucial for the construction of a vast array of chemical compounds.