2.4 Organic Com Flashcards
What is a functional group
Group/atom that gives the compound its characteristic properties
Suffix for alkanes
Ane
Suffix for alkenes
Ene
Prefix and suffix of halogenoalkanes
Prefix - the halogen
Suffix - ane
Suffix for alcohol (-OH)
Ol
Suffix for carboxylic acids (-COOH)
Oic acids
Prefix for 1, 2, 3, 4, 5, 6 carbons in chain
Meth, eth, prop, but, pent, hex
Rules when naming organic compounds
- identify longest C chain that contains functional group
- identity the functional group
- number the C atoms in chain in order that gives any side chains or substituted groups the smallest numbers possible
- if there are side chains- add them as prefixes (if more than 1 place in alphabetical order)
- if 2 or more of the same functional group or side chain use prefixes (di, tri, tetra)
Name the prefixes for these side chains, Cl, I, Br, F, 1C, 2C, 3C
Chloro, iodo, bromo, floro, methyl, ethyl, propyl
What does empirical formula show
Simplest whole number ratio of atoms of each element
What does molecular formula show
True number of atoms of each element
What does general formula show
All members of a homologous organic series
General formula of alkanes
CnH2n+2
General formula of alkenes
CnH2n
What does structural formula show
Structural arrangement of atoms within a molecule
what does Displayed formula show
Every atom and every bond in an organic compound
What does skeletal formula show
Carbon/hydrogen backbone of the molecule as a series of bonds with any functional groups attached
Effect of chain length on boiling temperature
Increases along with increasing length of chain
Due to increasing VDW forces
• chain branches reduce ability to form VDW - lower boiling temperature
Effect of chain length on solubility
Increasing hydrocarbon chain decreases solubility
Due to hydrocarbon chains not interacting with H2O
How does functional group affect boiling temperature
If the molecule is polar (has permanent dipole interactions) or can hydrogen bond- will have high boiling temperature eg alcohol
How does functional group affect solubility
- If only Van Der Waals- cannot dissolve in water as not enough attractions with polar water molecules
- If it can hydrogen bond it will form them with water and dissolve
- solubility of alcohols and carboxylic acid decreases as chain length increases as hydrocarbon chain increases so large hydrophobic effect makes it insoluble
What is a structural isomer
Compounds with same molecular formula but different structural formula
What are the 3 types of structural isomerism
Chain, position and functional group
Chain isomerism
C chain arranged differently
Position isomerism
Functional group in different position
Functional group isomerism
Functional group is different
What is stereoisomers
Same structural formula with different arrangement of groups
Examples of stereoisomers
E/Z isomers and optical isomers
Why does E/Z isomers occur
In alkenes due to restricted rotation around the double bond
What is a Z isomer
Priority groups on Zame side
What is an E isomer
Priority groups on oppositE sides
How to assign priority in e/z isomers
Atoms with highest Ar/Mr that us directly attached to C=C
Why does E isomers tend to have stronger intermolecular forces and higher melting temperatures
Can pack together better than Z
What is an electrophile
- Electron deficient species that can accept a lone pair of electrons
- have positive charge or delta +
- attack electron rich areas (negative)
Common electrophiles
- H delta+ from HBr or H2SO4
* Br delta + from Br2
What is a nucleophile?
- Electron rich species that can donate a lone pair of electrons
- have negative charge/ lone pair of electrons (must be shown)
- attack positive or electron deficient areas
- involved in nucleophilic substitution reactions with halogenoalkanes to form nitriles, amines and alcohols
Common nucleophiles
- hydroxide ion -:OH
- cyanide ion -:CN
- ammonia molecule :NH3
What is a radical?
- Species with an unpaired electron (show as a dot next to chemical symbol)
- very reactive
- UV light breaks down the bond - homolytic fission
- Attack alkanes during halogenation
Example of radical
Cl•
What is bond fission
Splitting of a covalent bond
What is heterolytic bond fission
One of bonded atoms receives both electrons from the covalent bond
Ions are formed
What is homolytic bond fission
Each of the bonded atom receives one of the bonded electrons
Produces radicals
