Methane has a tetrahedral geometry which results from sp3 hybridization. This hybridization allows for four equivalent bonds arranged at 109.5° angles.

Alcohols are defined by the presence of a hydroxyl (-OH) group attached to a saturated carbon atom. This group is responsible for the typical reactivity and polarity of alcohols.

Alkenes contain at least one carbon-carbon double bond. Ethene is the simplest alkene with its characteristic C=C bond, unlike the other options which lack this feature.

Constitutional isomers share the same molecular formula but differ in the connectivity of their atoms. This is distinct from stereoisomers, where atoms are connected in the same order but arranged differently in space.

Aromatic compounds are defined by a cyclic, planar structure with delocalized pi electrons, which provides extra stability. This delocalization follows Huckel's rule and distinguishes aromatics from other cyclic compounds.

In SN2 reactions, the nucleophile attacks the electrophilic carbon from the opposite side of the leaving group. Steric hindrance around that carbon is the key factor that can slow down the reaction.

PCC is a mild oxidizing agent that stops the oxidation at the aldehyde stage when reacting with primary alcohols. Stronger oxidants like KMnO4 typically oxidize alcohols all the way to carboxylic acids.

SN1 reactions proceed through a two-step mechanism where the leaving group departs first, forming a carbocation intermediate. This intermediate is then attacked by the nucleophile in the subsequent step.

The E2 mechanism is a concerted process where the base abstracts a proton while the leaving group departs simultaneously. This one-step mechanism differentiates E2 from the stepwise E1 mechanism.

CH3CH2COOH is a three-carbon carboxylic acid, which is systematically named propanoic acid. This adheres to IUPAC nomenclature rules, differentiating it from acids with different chain lengths.

DMF (dimethylformamide) is a polar aprotic solvent that does not extensively solvate nucleophiles, thereby enhancing their reactivity in SN2 reactions. Protic solvents like water and ethanol tend to hinder this reactivity.

Hydrogen bonding occurs when a hydrogen atom attached to a strongly electronegative atom (such as oxygen, nitrogen, or fluorine) interacts with a lone pair on another electronegative atom. This interaction is a significant form of dipole-dipole attraction in organic molecules.

Markovnikov's rule states that in the addition of HBr to propene, the hydrogen attaches to the carbon with more hydrogen atoms, leading to the formation of the more stable secondary carbocation. This results in 2-bromopropane as the major product.

Geometric isomerism, often referred to as cis-trans isomerism, arises from the restricted rotation around a double bond, resulting in different spatial arrangements of substituents. This is distinct from structural isomerism, where the connectivity of atoms differs.

The hydrogenation of alkenes involves adding hydrogen (H2) across the double bond in the presence of a metal catalyst like palladium or platinum. The catalyst facilitates the adsorption and reaction of hydrogen with the alkene.

According to Zaitsev's rule, elimination reactions favor the formation of the more substituted alkene. In this reaction, abstraction of the appropriate beta hydrogen leads predominantly to 2-methyl-2-butene.

Epoxidation with peracids, known as the Prilezhaev reaction, occurs via a concerted mechanism through a cyclic transition state. This simultaneous formation of the epoxide ring and carboxylic acid bypasses any discrete intermediate formation.

Racemization is the process by which a chiral substance converts into an equal mixture of its enantiomers, known as a racemic mixture. Such a mixture has no net optical activity because the effects of the two enantiomers cancel each other out.

Benzene is best described by a resonance structure in which the pi electrons are evenly distributed over all six carbon atoms. This delocalization leads to equal bond lengths around the ring, contributing to benzene's stability.

The greater acidity of carboxylic acids is largely due to the resonance stabilization of the carboxylate anion formed after deprotonation. This delocalization of the negative charge over two oxygen atoms makes the loss of a proton more favorable compared to alcohols.