Organic Chemistry Lecture 4

Alkanes are hydrocarbons that contain only single bonds between carbon atoms. They are relatively unreactive due to their non-polar covalent bonds.

The burning of alkanes in the presence of oxygen, releasing heat and light, forming carbon dioxide (CO2) and water (H2O).

This law states that the volumes of gases involved in a chemical reaction, at constant temperature and pressure, are in a simple ratio to each other.

This law states that equal volumes of gases at the same temperature and pressure contain the same number of molecules.

A technique used to determine the empirical formula of a hydrocarbon by reacting a known volume of the hydrocarbon with oxygen and measuring the volumes of the products (CO2 and H2O) and unreacted oxygen.

CxHy + (x + y/4)O2 -> xCO2 + (y/2)H2O

Combustion analysis can: 1) Determine the empirical formula of a hydrocarbon. 2) Determine the molecular weight of an alkane by knowing the volume of the hydrocarbon and the volumes of the products and unreacted oxygen.

The total volume of the product gases (CO2 and H2O) plus the unreacted oxygen is less than the original volume of the hydrocarbon and oxygen due to the formation of water (H2O), which is a liquid at room temperature.

A series of steps in a free radical reaction where the radical intermediates are continuously regenerated.

The final step in a free radical reaction where two radicals combine to form a stable molecule, ending the chain reaction.

An atom or molecule with an unpaired electron, making it highly reactive and seeking to pair up with another electron.

Bromine is more selective than chlorine or fluorine in free radical reactions, preferentially reacting with the most stable radical intermediate.

The stability of a free radical is determined by the number of alkyl groups attached to the carbon atom with the unpaired electron. More alkyl groups = more stable.

Free radicals are implicated in various diseases, especially those related to aging, by damaging biological molecules.

Free radicals can damage important biomolecules like DNA, proteins, and lipids, contributing to disease development.

Many age-related diseases are linked to free radical damage to biological molecules over time.

The simplest whole number ratio of atoms in a compound. It represents the relative proportions of elements, not the actual number of atoms.

The percentage by mass of each element in a compound. Found experimentally by determining the mass of each element in a given sample.

The actual number of atoms of each element in a molecule. Shows the exact composition of a molecule.

A reaction involving alkanes and halogens where a halogen atom is substituted for a hydrogen atom on the alkane. It proceeds via a free radical mechanism.

The first step in the free radical halogenation mechanism. It involves the homolytic cleavage of a halogen molecule into two free radicals.

The chain reaction steps in halogenation where a free radical reacts with an alkane molecule, forming a new free radical which then continues the cycle.

The final steps in halogenation where two free radicals combine to form a stable product. This stops the chain reaction.

A carbon that is directly bonded to just one other carbon atom.

A carbon atom bonded to two other carbon atoms.

A carbon atom bonded to three other carbon atoms.