Organic Chemistry Reactions PDF

Organic chemical Reactions SCH4U1 - Tsai Cracking Cracking in organic chemistry refers to the process of breaking down large hydrocarbon molecules into smaller, more useful ones. This process is particularly significant in petrochemistry, where it is used to convert long-chain hydrocarbon...

Organic chemical Reactions SCH4U1 - Tsai Cracking Cracking in organic chemistry refers to the process of breaking down large hydrocarbon molecules into smaller, more useful ones. This process is particularly significant in petrochemistry, where it is used to convert long-chain hydrocarbons derived from crude oil into shorter-chain hydrocarbons, including alkanes and alkenes. Types of Cracking Cracking can be categorized mainly into two types: 1. Thermal Cracking 2. Catalytic Cracking - Haber Process - Practice 1. Thermal Cracking Definition: This method involves the application of high temperatures (typically between 450°C to 750°C) and pressures (up to about 70 atmospheres) to break down large hydrocarbons into smaller molecules. Mechanism: Thermal cracking operates by breaking carbon-carbon bonds through a process that generates free radicals. The high energy input causes the hydrocarbons to decompose, resulting in a mixture of products that often includes alkenes, which are valuable for further chemical synthesis234. 2. Catalytic Cracking Definition: In this method, a catalyst (commonly zeolite) is used to facilitate the cracking process at lower temperatures (around 500°C) and moderate pressures. Mechanism: Catalytic cracking enhances the efficiency of the reaction by lowering the activation energy required. The catalyst helps in breaking C-C bonds and rearranging the molecular structure, leading to a higher yield of desirable products such as gasoline and other fuels345. Importance of Cracking Economic Value: Cracking increases the economic value of crude oil by transforming less useful heavy fractions into more valuable lighter fractions, such as gasoline and diesel15. Production of Key Chemicals: The process generates important feedstocks for the chemical industry, including ethylene and propylene, which are essential for producing plastics and other chemicals26. Summary In summary, cracking is a crucial chemical reaction in organic chemistry that enables the conversion of large hydrocarbon molecules into smaller, more useful compounds through thermal or catalytic processes. This transformation not only enhances the utility of petroleum products but also supports various industrial applications. Share Addition limited to chemical compounds that have multiple bonds, such as molecules with carbon–carbon double bonds (alkenes), or with triple bonds (alkynes), and compounds that have rings, Elimination In most organic elimination reactions, at least one H+ is lost to form the double bond It is a reverse reaction of addition, same mechanism as dehydration / oxidation Substitution also known as single displacement reaction or single substitution reaction one functional group in a chemical compound is replaced by another functional group Cyclization Organic Reaction Definition: Cyclization reactions involve the formation of cyclic compounds from acyclic precursors. This can occur through various mechanisms, including nucleophilic attacks and rearrangements. Mechanism: Cyclization typically occurs when functional groups in a linear molecule react with each other to form new bonds, resulting in a ring structure. Example: An example is the formation of tetrahydrofuran from 1,4-butanediol through intramolecular dehydration: HO CH2 CH2 CH2 OH→C4H8O+H2O Oxidation When a carbon atom in an organic compound loses a bond to hydrogen and gains a new bond to a heteroatom (or to another carbon), we say the compound has been dehydrogenated, or oxidized. A very common biochemical example is the oxidation of an alcohol to a ketone or aldehyde. Reduction Same mechanism as Addition when a carbon atom in an organic compound gains a bond to hydrogen and loses a bond to a heteroatom (or to another carbon atom), we say that the compound has been hydrogenated, or reduced. The hydrogenation of a ketone to an alcohol, for example. Esterification Formation of Ester. To do so, you would treat a carboxylic acid with alcohol and an acid catalyst. https://www.youtube.com/watch?v=JFnWitb47og  A reverse reaction of esterification Hydrolysis Hydrolysis of organic compounds in water usually depends on the concentrations of protons or hydroxide ion or both, as well as water. Mechanisms of hydrolysis are well-described by classical concepts of substitution or addition by HO− or H2O at sp3 or sp2 carbon. Polymerization (Synthesis) A process of reacting monomer molecules together to form polymer chains.