3.3.1- introduction to organic chemistry Flashcards
define empirical formula
simplest whole number ratio of atoms in a molecule
define molecular formula
gives the actual number of atoms of different elements in a molecule
define displayed formula
shows every atom and every bond in a molecule
define structural formula
shows arrangement of atoms in a molecule without showing every bond
define skeletal formula
drawn as lines with each vertex being a carbon atom. Carbon atoms aren’t drawn, assumed each C atom has all unspecified bonds as C-H
define homologous series
a group of compounds with the same functional group/general formula. Compounds in a homologous series will react similarly.
Alkanes
-hydrocarbon
- have no c=c double bonds so are saturated
- end in ‘ane’
-general formula - CnH2n+2
Alkenes
-hydrocarbon
-has C=C double bonds so is unsaturated
-ends in ‘ene’
-has C=C functional group
- number needed for naming (where double bond is)
Halogenoalkanes
- has additional group 7 element
- C-X functional group where X is a group 7 element
-Cl= chloro, Br= bromo, I= iodo - need number for naming
Alcohols
- ends in ‘ol’ (sometimes number needed)
OH functional group - general formula= Cn, H2n+1, OH
Carboxylic Acids
- ends in ‘anoic acid’
- COOH functional group
- always at end of chain (no number needed for naming)
Aldehydes
- have C=O functional group
- ends in ‘anal’
- at end of chain
Ketones
- have C=O functional group
- ends in ‘one
- middle of chain
- sometimes need numbers for naming
prefix for CH3 group
methyl
prefix for C2H5 group
ethyl
prefix for C3H7 group
propyl
prefix for C4H9 group
butyl
define structural isomers
when molecules have the same molecular formula but a different structural formula
define positional isomerism
functional group is attached to the main chain at a different place
define functional group isomerism
same atoms but a different functional group due to a different arrangement of atoms
define chain isomerism
hydrocarbon chain organised differently, e.g. branched chains
define stereoisomerism
when molecules have the same structural and molecular formula, but have a different arrangement of atoms in space
What is E-Z isomerism?
- E-Z isomerism is caused by limited rotation about C=C double bonds
- highest values (atomic number) opposite = E
- highest values (atomic number) together= Z
priority rules
- choose lowest number as top priority
- if numbers are the same then use priority list (halogens-alkyl-alkenes-everything else)
