Organic chemistry Some last things.

Organic chemistry What are the basics of organic chemistry? Organic molecules contain carbon. Exceptions are carbides, carbon oxides and carbonates. Carbon can form 4 covalent bonds. Oxygen forms 2 covalent bonds. Hydrogen and halogens form one. CH 3 -CH 2 -CH 3 CH 2 =CH-CH 3

Organic chemistry What are functional groups? Functional groups act like one molecule. They change chemical reactivity. They change properties of the molecule.

Organic chemistry What is a homologous series? A homologous series is a group of hydrocarbons (or other molecules) with an additional link added to the chain. This changes the properties in a predictable way. They include alkanes, alkenes, alcohols, carboxylic acids, etc

Organic chemistry How do homologous series characteristics change in a predictable manner? As you get more carbons in alkanes, you get more van der Waals’ forces. So, the more carbons, the more likely to be liquid at room temp.

Organic chemistry How do functional groups change properties of molecules? Functional groups allow for hydrogen bonding and polarity to increase intermolecular forces. Methane = nonpolar Methanal = polar Methanol = highly polar

Organic chemistry How does the effect change solubility in water? Non-polar molecules are not very soluble. The more polar, the more soluble. The longer the chain, the less soluble due to increase in non-polar area. Ethanol vs Hexanol ??

Organic chemistry What are isomers? Isomers are molecules that have the same formula, but a different structure. Different structures change the properties. What are the different structures of C 6 H 14 ? Structural isomers are joined in a different order. Sterioisomers have a different arrangement in space.

Organic chemistry Position isomers have a functional group in a different position. Hydrocarbon chain isomers have different parent chains with carbon functional groups. Alcohol and ether, alkene and cycloalkane, aldehyde and ketone, carboxylic acid and ester.

Organic chemistry What is complete and incomplete combustion? When burned in oxygen, complete combustion leads to carbon dioxide and water. When burned in limited oxygen supplies, some carbon monoxide or carbon is formed.

Organic chemistry What are reaction pathways? Reaction pathways give you a path from one molecule to a new molecule. Many times it requires more than one reaction (hence a pathway).

Organic chemistry What are some common pathways? Substitution reactions substitute one atom for another (halogen for a carbon). Depending on time, temp, concentration will determine how many H are replaced. A free radical chain reaction is a reaction with an alkane and a halogen. Initiation creates the radicals. (Cl) Propagation forms most of the product. (reacting) Termination consumes the radicals. (end)

Organic chemistry What else? Addition reactions use the double bond of an alkene (or triple of alkyne) to create a single bond and new functional group. Addition polymerisation creates long chains (polymers) of repeating monomers.

Organic Chemistry What are the reaction pathways? These are steps an organic compound can go through to reach a new compound. dihalogenalkane Halogenalkane Trihalogenalkane tetrahalogenalkane alkene alkane alcohol Primary secondary ketonealdehydeCarboxylic acid