Benzene Chemistry Quiz

The process in which the electrons in the π bonding system of benzene are not localized to specific carbon atoms but are spread out over all six carbon atoms.

Each carbon atom in benzene contributes one electron to form a π bond, which is not a localized bond between two carbon atoms like in alkenes, but is spread over all six carbon atoms.

The three σ bonds that each carbon atom forms in benzene: one with each neighboring carbon atom and one with a hydrogen atom.

Aromatic compounds with a functional group directly attached to the benzene ring.

The number of electrons involved in the π bonding system of a benzene molecule.

A shorthand way to write the benzene ring structure, using a circle to represent the delocalized π electron system.

The group of carbon atoms and their attached hydrogen atoms that are derived from a benzene ring when one hydrogen atom is removed.

A compound with a nitrogen atom directly attached to the benzene ring.

A type of chemical reaction where an atom or group of atoms is exchanged for another atom or group of atoms, while the overall structure of the molecule remains largely unchanged. In benzene, this involves replacing one or more hydrogen atoms with another atom or group.

A compound that is attracted to areas of high electron density. In the context of arenes, they are often positively charged species that attack the electron-rich benzene ring.

A positively charged species (cation) that is formed when a Br2 molecule reacts with AlBr3 in the presence of benzene. This species is an electrophile and initiates the electrophilic substitution reaction by attacking the benzene ring.

The electrons in the π bonding system of benzene are not localized to specific carbon atoms but are spread out over all six carbon atoms. This creates a highly stable ring and explains the resistance of benzene to addition reactions.

A molecule containing a benzene ring with three bromine atoms attached at positions 1, 3, and 5 on the ring.

A molecule containing a benzene ring with two chlorine atoms attached at positions 1 and 3, and a nitro group attached at position 5.

A group of molecules that have a benzene ring as their core structure. These molecules often undergo electrophilic substitution reactions due to the electron-rich nature of the benzene ring.

Involves the introduction of a nitro group (-NO2) into a molecule using an electrophilic substitution reaction.

The positively charged NO2+ ion, formed from nitric acid and sulfuric acid, acting as the attacking species in nitration.

The mixture of concentrated nitric acid and concentrated sulfuric acid used to generate the nitronium ion for nitration.

A reaction where an electrophile (electron-seeking species) attacks a benzene ring, replacing a hydrogen atom with the electrophile.

The nitro group (-NO2) attached to a benzene ring makes the ring less reactive towards further electrophilic aromatic substitution at the 2 and 4 positions.

The tendency of a substituent on a benzene ring to direct further electrophilic substitution to specific positions.

The product formed by the nitration of methylbenzene (toluene), where a nitro group is added to the benzene ring.

The product formed by the nitration of toluene where the nitro group is located at the 2, 4, or 6 positions relative to the methyl group.

The substitution of a hydrogen atom on a benzene ring with a halogen atom, using a Lewis acid catalyst like aluminum chloride.

A reaction where a hydrogen atom on an alkyl side chain of an aromatic compound is replaced by a halogen atom. This is a free radical reaction.

The ability of an atom or group to donate electrons, making the molecule more reactive.

When multiple substitutions occur on the benzene ring, especially if they occur at the 2, 4, and 6 positions, because these positions are activated by the electron-donating groups.

The C-H bond in the benzene ring is less reactive than the C-H bond in an alkane due to the electron delocalization in the benzene ring.

The nitration of benzene involves the introduction of a nitro group (-NO2) onto the benzene ring, using concentrated nitric acid and sulfuric acid as catalysts.

The relative positions of substituents on a benzene ring, with the 1 position designating the carbon atom where the main functional group is attached.

The process of introducing a sulfonic acid group (-SO3H) onto a benzene ring.

A type of electrophilic aromatic substitution that introduces an alkyl group (like -CH3 or -C2H5) onto a benzene ring.

A type of electrophilic aromatic substitution that introduces an acyl group (containing a carbonyl group, C=O) onto a benzene ring.

In Friedel-Crafts reactions, the electrophile is a carbocation, a positively charged carbon atom. It is formed by adding an aluminum chloride (AlCl3) catalyst to a halogenoalkane or an acyl chloride.

A three-step mechanism that describes the alkylation of benzene, where an alkyl chain is introduced into the benzene ring.

The process of creating new compounds by changing the structure of existing arenes, often involving Friedel-Crafts reactions.

The ability of benzene to undergo electrophilic substitution reactions, where an electrophile replaces a hydrogen atom on the benzene ring.

The molecule that attacks the benzene ring in electrophilic substitution reactions. It is typically a positively charged species.

Alkylation of benzene is a reaction where an alkyl group replaces a hydrogen atom on the benzene ring. It is a type of electrophilic aromatic substitution reaction. The product is an alkylbenzene.

Acylation of benzene is a reaction where an acyl group replaces a hydrogen atom on the benzene ring. It is a type of electrophilic aromatic substitution reaction. The product is an acylbenzene.

The electrophile is an electron-deficient species that attacks the electron-rich benzene ring in electrophilic aromatic substitution reactions like alkylation and acylation. It is often a carbocation or acylium ion.

The benzene ring is a cyclic, planar molecule with six carbon atoms and six hydrogen atoms. It has a unique electronic structure that makes it highly reactive to electrophilic attack.

In the alkylation and acylation of benzene, the catalyst (usually AlCl3) regenerates itself in the final step. The catalyst is essential for the reaction to proceed, but it is not consumed in the process.

The alkyl side-chain of an alkylarene, like methylbenzene, can be oxidized using a strong oxidizing agent, e.g., potassium manganate(VII), under reflux conditions. This reaction converts the alkyl side-chain to a carboxylic acid.

Hydrogenation of benzene is a reaction where the unsaturated benzene ring is converted to the saturated cyclohexane ring. This reaction requires hydrogen gas and a catalyst, typically nickel or platinum.

The reaction of benzene or its derivatives with hydrogen gas to form a saturated ring is classified as an addition reaction because the hydrogen atoms are added to the benzene ring, breaking the double bonds, and creating a single bond between each carbon.