module 4.1- core organic Flashcards
define organic chemistry
study of the structure, properties, composition, reactions and preparation of carbon-containing compounds
why is carbon so special?
in group 4, each carbon can form four covalent bonds to other atoms, can form long chains with triple or double bonds
define saturated (in terms of hydrocarbons)
contains only single bonds, fully saturated carbons
are alkenes saturated or unsaturated?
unsaturated as they contain a carbon-carbon double bond
define homologous series
a family of compounds with similar chemical properties whose SUCCESSIVE members differ by the addition of a -CH2- group
define functional group
the part of the organic molecule that is largely responsible for the molecule’s chemical properties.
what are the three classes of hydrocarbons
aliphatic - carbon atoms joined to each other in unbranched (straight) or branched chains, or non-aromatic rings
alicyclic - carbon atoms are joined to each other in a ring (cyclic) structure, with or without branches
aromatic - some or all of the carbons are found in a benzene ring
what does the stem, prefix and suffix indicate about hydrocarbons
stem - indicates the number of carbon atoms in the longest continuous chain of the molecule
prefix - indicates the presence of side chains or functional groups
suffix - indicates functional groups
what are the three homologous series of aliphatic hydrocarbons that you need to know
alkanes - single carbon-to-carbon bonds
alkenes - double carbon-to-carbon bonds
alkynes - triple carbon-to-carbon bonds
how do you name aliphatic alkanes
(4steps)
- all alkanes have the suffix -ane
- identify the longest continuous chain of carbon atoms and name it
- identify side chains attached to “parent chain”. the name of the alkyl group is added as a prefix to the name of the parent chain
- add numbers before any alkyl groups to show the position of the alkyl groups on the parent chain
how do you name alicyclic alkanes ?
same as aliphatic alkanes but add the prefix cyclo- to show carbon atoms are arranged in a ring structure
what is the functional group and suffix of an aldehyde
-CHO (oxygen double bonded to carbon)
suffix= -al
what is the functional group and suffix of a ketone
-C(CO)C- (co double bond)
suffix = -one
what is the functional group and suffix of an ester
-cooc- (first oxygen double bonded)
-oate = suffix
what is the functional group and suffix of an acyl chloride
-COCl (carbon and oxygen double bonded)
suffix = -oyl chloride
what is the functional group and prefix AND suffix of an amine
-NH2
prefix= amino-
suffix= -amine
what is the functional group and suffix of a nitrile
-CN (triple bond)
suffix = -nitrile
how do you write the skeletal formula
a line represents a single bond
an intersection of two lines represents a carbon atom
the end of a line represents a CH3 group
define nomenclature
the system used for naming organic compounds
what is the difference between molecular and empirical formula
empirical is the simplest whole number ratio of atoms whereas molecular is the actual number of atoms of different elements in a molecule
what does displayed formula mean
shows every atom and every bond in a molecule
give the suffixes for:
1. no double bonds
2. at least 1 double bond
3. an alcohol
4. an aldehyde
5. a ketone
6 a carboxylic acid
- -ane
- -ene
- -ol
- -al
- -one
- oic acid
define structural isomerism
when molecules have the same molecular formula but different structural formula
what are the 3 types of structural isomerism
chain - different chain length caused by branching
positional - position of the functional group changes
functional group - composition of the compound can change the functional group
what are the 3 functional group isomers of C3H8O
propan-1-ol
propan-2-ol
methoxethane - ether - 2 carbonds bonded directly to oxygen (COC) not (COH)
how can isomers change the physical properties of a compound
Different intermolecular forces between molecules can lead to differences in
boiling/melting points, viscosities, solubilities, densities etc.
how can isomers change the chemical properties of a compound
Different functional groups can have different interactions with biological systems
(toxicity), reactivity, bond enthalpy, flammability, oxidation states etc.
what makes alkanes saturated
only contains single sigma bonds
what is a sigma bond
a strong covalent bond formed by overlap of atomic orbitals along the bond axis (i.e. on the line connected by the 2 bonded atoms)
what does having a sigma bond mean for the atoms mobility
atoms can rotate freely around a sigma bond and molecule shapes are not rigid.
what is the shape of alkanes and why is it like this?
tetrahedral 109.4 degree bond angle
because each carbon is surrounded by 4 electron pairs in four sigma bonds. the repulsion of these electron pairs results in the 3D tetrahedral arrangement around each carbon atom
what is the order of priority in nomenclature for the function groups
highest - lowest
and their suffix/ prefix
carboxylic acid -oic acid
ester -oate
amide -amide
nitrile -nitrile
aldehyde -al
ketone -one
alcohol -ol or hydroxy-
amine -amine or amino-
alkene -ene
alkyne -yne
alkane -ane
ether alkoxy-
alkyl halide halo-
what are the two types of bond fission?
homolytic fission - each of the bonded atoms takes one of the electrons from the covalent bond
heterolytic fission - one of the atoms takes both electrons from the covalent bond resulting in a negative and positive ion
what do reaction mechanisms tell you?
HOW the reaction takes place
what do curly arrows in reaction mechanisms tell you
show the movement of the electron pairs when bonds are broken or made
what is a radical
an atom or group of atoms with an unpaired electron