Basic Organics Flashcards
What is a Functional Group?
The group of atoms that is responsible for the characteristic reactions of a molecule
What is a General Formula?
Algabraic form of a homologous series e.g. CnH2n+2 for alkanes
What is a Homologous Series?
A Family of coumpounds with the same general formuka and similar chemical properties
What is a Structural Formula?
A Compound shown carbon by carbon with side groups listed in between
e.g. butane: CH3CH2CH2CH3
What is a Displayed Formula?
A Compound shown by drawing every bond between every atom in the complete structure
What is a Skeletal Formula?
A Compound shown without hydrogens and carbons, instead being represented by the corners of the chain, with extra side groups being draw in full
What are Aromatic Compounds?
An organic compound that contains a benzene ring
What are Alicyclic Compounds?
An organic compound that contains carbon and hydrogen joined together in a non-aromatic ring
What are Alkyl Groups?
A hydrocarbon fragment with the general formula: CnH2n+1
What are Saturated Compounds?
Compounds that only have single bonds in the structure
What are Unsaturated Compounds?
Compounds that have a double or tripple bond in the structure allowing it to react
What is Homolytic Fission?
When a covalent bond is broken between 2 atoms and 1 electron from the bond goes to each atom
What is Heterolytic Fission?
When a covalent bond is broken between 2 atoms and the electron pair goes to one of the atoms
What is a Radical?
An atom at least 1 unpaired electron in its outer shell, making it very reactive
What is a Isomer?
A Compound with the same molecular formula, but different structural formula
What is a Sterioisomer?
A Compound with the same molecular formula and structural formula, but different arrangment of atoms. Typically seen in alkenes due to the C=C
What is an electrophile?
Any particle that can accept an electron pair
What are all of the functional groups and their names?
-X where X is a halogen: Haloalkanes
-OH: alcohol
C=C: alkene
-CHO: aldehyde
CO (in the middle of a compound): keytone
-COOH: Carboxylic acid
Why do alkane boiling points increase as they get longer?
Longer chains have more points of contact with surrounding molecules, increasing the energy required to overcome the london forces between molecules, increasing boiling point.
Why does an isomer of an alkane that has more alkyl groups have a lower boiling point?
More alkyl groups cause fewer points of contact with surround molecules, leading to less energy required to overcome weaker london forces, decreasing the boiling point.
What reaction do alkanes do?
Combustion
What reactions can alkenes do?
Addition reactions
Combustion
What is the difference between a Sigma bond and Pi bond?
Sigma bonds have direct overlap of orbitals between the two bonded atoms.
Pi bonds have overlap above and below the plane of the atoms
Pi bonds are weaker than Sigma bonds
Why is a C=C not twice the strength of C-C?
C-C has a Sigma bond
C=C has a Sigma bond and a Pi bond
Pi bonds are weaker than Sigma bonds, therefore C=C is not twice the energy to overcome than a C-C
What is E-Z isomerism?
When both Carbons in a C=C have 2 different groups bonded to them
With E being that the different groups are on opposite sides
And Z being on the same side
What is Cahn-Ingold-Prelog rules?
States what is considered to be the “different group” when writing E-Z isomerism
There are two rules:
1. Rank bonded atoms by atomic number, highest atomic number takes priority
2. If they are the same atomic number, continue down the chain until one chain has a higher atomic number than the other
e.g. CH2CH3 has a higher priority than CH3 due to C>H on the second bond of the chains
State and Outline what is the mechanism for methane reacting with chlorine?
Radical Substitution
3 Stages:
Intiation: Cl2 -(UV light)> Cl* + Cl*
Propagation: CH4 + Cl* -> CH3* + HCl
CH3* + Cl2 -> CH3Cl + Cl*
Termination: CH3* + Cl* -> CH3Cl
Cl* + Cl* -> Cl2
this reaction can further continue on the products making even more halogenated methanes
State and Outline the machanism for alkene addition reactions?
Electrophilic Addition
(DO THIS VIA DRAWING DIAGRAMS)
Electrophile approaches the alkene, and becomes polarized due to the region of high electron density at the C=C
The delta positive atom bonds to one of the carbons, leaving a carbocation and a negatively charged atom
The negativly charged atom and carbocation attract each other and bond forming the product
What is Markovnikov’s rule?
States what products are most likely to form when an unsymetrical alkene is undergoing an addition reaction.
Hydrogen’s are more likely to go to the carbon with more hydrogens bonded to it, known as the major isomer
Why is Markovnikov’s rule true?
Carbocations with more alkyl groups are more stable, due to the bonding pair of electrons being in the middle of the carbons, they can be pulled closer to the carbocation increasing its stability.
What is polymerisation?
When monomers join together to create an n length polymer
What type of polymerisation do alkenes undergo?
Addition polymerisation
What is the repeating unit of a polymer?
The monomer that forms it
What is Cis-Trans Isomerism?
If both C=C carbons have a hydrogen and another group, it can be classed as Cis-Trans isomerism. Cis being the hydrogen on the same side, Trans being the hydogen on different sides
