Isomers Alkenes and Alkanes

What is the result of the complete combustion of alkanes?

Produces carbon dioxide (CO₂) and water (H₂O), yielding maximum energy efficiency.

Complete combustion of alkanes formula

CnH_{2n+2} + (1.5n + 0.5)O_2 → nCO_2 + (n+1)H_2O

What occurs during incomplete combustion of alkanes?

Forms carbon monoxide (CO) or elemental carbon (C) along with water (H₂O), leading to reduced energy output and toxic byproducts.

Types of unsaturated hydrocarbons

Alkenes, Alkynes, Aromatic Compounds.

Alkenes formula

CnH2n; they contain at least one double bond and are used in synthesis.

Alkynes formula

CnH2n-2; they contain at least one triple bond and are utilized in complex molecule synthesis.

What are aromatic compounds?

Compounds that feature benzene rings, widely present in natural and synthetic materials.

Why do alkenes have higher reactivity than alkanes?

Due to the presence of double or triple bonds, which participate in addition reactions.

What is hydrogenation in addition reactions of alkenes?

An alkene reacts with H₂ in the presence of a metal catalyst (e.g., Pt, Pd, Ni), converting the double bond into a single bond.

What is halogenation in addition reactions of alkenes?

A reaction with halogens (Cl₂, Br₂) that forms dihalides.

Describe hydrohalogenation of alkenes.

A reaction with hydrogen halides (e.g., HCl, HBr, HI), following Markovnikov's rule.

What type of reaction is hydration in alkenes?

Addition of H₂O, often forming alcohols.

Constitutional isomers

Isomers that have the same molecular formula but different atom connectivity.

Stereoisomers

Isomers that have the same connectivity but different spatial arrangements (e.g., cis-trans isomers).