✅6 - Organic Chemistry I Flashcards
What is a functional group?
The group of atoms which gives an organic compound its characteristic properties and reactions
What is a hydrocarbon?
A compound of hydrogen and carbon only
What is a homologous series?
Family of compounds which all contain the same functional group and each member of there series contains one CH2 unit more than the previous member
What is a general formula?
Represents all the members of a homologous series
Why can carbon form so many compounds?
- the atoms have an exceptional ability to form chain, branches chains and rings of various sizes
- Carbon is relatively inert and unreactive when in C-C or C-H bonds
What is empirical formula?
The simplest whole number ratio of atoms in a compound
What is molecular formula?
The actual number of atoms in each molecule
What is structural formula?
Shows the arrangement of atoms carbon by carbon with the attached hydrogens and functional groups
What is skeletal formula?
Shows the bonds of the carbon skeleton only, with any functional groups
What is displayed formula?
Shows how all the atoms are arranged, and the bonds between them, drawn out
What is addition?
Joining two or more molecules together to form a larger molecule
What is polymerisation?
Joining together lots of simple molecules to form a large one
What is elimination?
When a small group of atoms breaks away from a larger molecule
What is substitution?
When one species is replaced by another
What is hydrolysis?
Splitting a molecule into two molecules by adding H+ and OH- derived from water
What is a species?
An atom, an ion, a radical or a molecule
What is a nucleophile?
An electron pair donor, often negatively charged ions or species with a lone pair
What are nucelophiles attracted to?
A delta positive Carbon
What is an electrophile?
Electron pair acceptors, positively charged ions attracted to electron rich areas
What is a radical?
A species with an unpaired electron
What are structural isomers?
The molecular formula is the same but the structural formula is different
What are chain isomers?
The carbon chain is arranaged differently
What are positional isomers?
Where the functional group is attached to a different carbon
What are functional group isomers?
The isomers have different functional groups
Can atoms rotate around a C-C bond?
Yes
What type of hydrocarbons are alkanes?
Saturated
What are the two types of fission?
Homolytic and heterolytic
What is heterolytic fission?
The bond breaks unevenly with one of the bonded atoms recieving both electons from the bonded pair
What is homolytic fission?
The bond breaks evenly and each bonding atom receives one electron from the pair
What does heterolytic fission produce?
Two ions, one + and one -
What does homolytic fission produce?
Two radicals
In what reactions do alkanes react with halogens?
Free radical substitution
What are the steps of free radical substitution?
Initiation
Propagation
Termination
What is photodissociation?
When radicals are produced by sunlight in Cl-Cl bonds
What happens in propagation reactions?
Radicals are created and used up
What can happen in propagation between methan and a chlorine radical?
Cl. + CH4 ——> CH3. + HCl
.CH3 + Cl2 ——> CH3Cl + Cl.
What happens in termination reactions?
Radicals are used up as they react with each other
What is the main problem with free radical substitution?
A mixture of products is created
What is crude oil mainly made up of?
Alkanes
What temperature is used to vaporise crude oil?
350 degrees C
Why don’t the largest hydrocarbons vaporise?
Their boiling points are too high
What happens to the vapour as it moves up the fractionating column?
It cools, and each fraction condenses at a different temperature
What happens to the hydrocarbons with the lowest boiling points?
The don’t condense, they’re drawn out as gases at the top of the column
How can the heaviest fractions be used?
They can be ‘cracked’ to form smaller molecules