Chapter 11 - Basic concepts of Organic chemistry Flashcards
what is a homologous series?
- members of a homologous series are similar:
- same functional group
- differ from successive members by a unit of CH2
- have similar chem & physical properties - properties show a gradation
how do we name organic compounds?
using the IUPAC Nomenclature
name can be split into:?
- prefix
- stem
- suffix
prefix?
- 1st part of name
- indicates other groups apart from the main functional group
stem is derived from?
longest C chain - MUST BE LONGEST
how is the position shown?
Number AND hyphens
where are functional groups included in the name of the mol?
- can be contained in diff parts of the mol:
- Suffix - if most imp FG
- Prefix - if they are an additional FG
Alcohol FG?
- OH
- Prefix: Hydroxy-
- Suffix: ol
Aldehyde FG?
- c double bonded to O and single bonded to H
- suffix: al
alkanes FG?
C-C
end in -ane
what are alkyl groups?
- resemble alkanes - e.g. Methyl, ethyl
- have 1 fewer H atom than alkanes giving them the GF: CnH2n+1
- letter R usually but not always represents Alkyl group
Alkene GF?
- C=C
- suffix: -ene
carboxylic acid FG?
- C double bond O, single bond OH
suffix: -oic acid
haloalkanes prefixes?
- F - Fluoro-
- Cl - Chloro-
- Br- Bromo-
- I - iodo-
ketone FG?
- 3 C’s with middle one double bonded to O
- suffix: -one
displayed formula REMEMBER TO?
Show all atoms and bonds - EVEN BETWEEN O-H
to get empirical formula?
divide molecular formula by largest number that goes into both
2 types of isomer?
- structural
- stereoisomers
the 3 types of chain isomerism?
- chain isomerism
- position isomerism
- functional group isomerism
what is chain isomerism?
molecules with a diff carbon chains
what is position isomerism?
molecules with the same functional group that is attached in diff positions
what is functional group isomerism?
molecules with the same molecular formula but different functional groups
What is the stem when there is 1 carbon?
Meth
what is the stem when there are 2 carbons?
eth
what is the stem when there are 3 carbons?
prop
what is the stem when there are 4 carbons?
but
what is the stem when there are 5 carbons?
pent
what is the stem when there are 6 carbons?
hex
what is the stem when there are 7 carbons?
hept
what is the stem when there are 8 carbons?
oct
what is the stem when there are 9 carbons?
non
what is the stem when there are
10 carbons?
dec
Definition: empirical formula?
A formula that shows the simplest whole number rate of atoms of each element present in a compound
Definition: molecular formula?
A formula that shows the number and type of atoms of each element present in a molecule
Definition: displayed formula?
A formula that shows the relative positioning of all the atoms in a molecule and the bonds between them.
⭐every single bond must be shown
Definition: structural formula?
a formula showing the minimal detail for the arrangement of atoms in a molecule
e.g. CH3CH2CH2CH3
Definition: skeletal formula?
a simplified organic formula, w H atoms removed from alkyl chains, leaving just a C skeleton and associated functional groups.
Definition: general formula ?
the simplest algebraic formula of a member of a homologous series. For example, the general formula of alkanes is CNH2N+2
Definition: 3-D formula?
a formula that shows the atoms arranged in 3 dimensions (TOPIC 6!)
Definition: saturated hydrocarbon?
a hydrocarbon w single bonds only
- SATURATED, SINGLE BONDS, SS
Homologous series definition?
a series of organic compounds with the same functional group but with each successive member differing by CH2
- they have the same chemical properties so react similarly
isomers have the same ? but different ?
isomers have the same molecular formula but different structural formula
complete combustion equation?
C6H14 + 91/2 O2 -> 6CO2 +H20
Carbon dioxide and water produced
why are some hydrocarbons responsible for incomplete combustion?
- a lot of O2 would be required for it to burn completely
- limited supply in O2 in a car engine -> incomplete combustion
WATCH OUT FOR?
MOLECULES GOING AROUND CORNERS - NEEDS TO BE THE LONGEST C CHAIN
brackets on the end of a structural formula are usually a ?
branch
what happens when you add an alkane or alkene to bromine?
2 layers form cos they don’t mix w water
what happens when an alkane is added to Br water?
- the Br is in the upper orange layer bc they are both covalent so Br dissolves cyclohexane. Very slowly, the Br upper layer decolorises, light makes this happen faster
what happens when an alkene is added to Br water?
bromine water DECOLOURISES immediately - orange ➡ colourless
this is a test for C=C
Burning Cyclohexane vs burning cyclohexene?
when cyclohexene burns, there’s a lot of black smoke which is unburnt C particles. Cyclohexane, burns cleanly- no black smoke, alkanes burn cleanly
why are alkanes so unreactive?
- there is only a small difference in electronegativoty between C&H meaning
RULES FOR NAMING branched alkanes
- identify longest C chain and count it - can go around corner!!!!
- count it
- name the any branches using -yl ending (alkyl gr)
- add the number the branch is coming of onto the branch using a -
- number-branchstem
isomers?
add methyl groups, rarely use ethyl ones
naming: count from which side?
the side that gives the lowest numbers
naming: use what to indicate the number of groups?
di, tri, tetra
naming: to say the position of multiple groups, use what?
a comma to separate the numbers
naming: if there are 2 or more substituent groups place the names in?
alphabetical order
naming: if there are 2 or more substituent groups, use?
dashes for numbers and between the grs - e.g. 4-ethyl-6-methylnonane
summary of naming steps?
1) how long is the C chain
2) if only C&H, are there double bonds (-ene) or triple bonds (-yne)
3) other groups? - add appropriate ending
4) if the parent functional gr is on C1, leave no. off
naming: placement of numbers?
the no for the groups goes IN the name, number for branch goes b4
naming: the most weighted FG is?
The carboxylic acid
what is a functional group?
the part of a molecule that is largely responsible for the molecule’s chemical properties
hydrocarbons can be classified as?
aliphatic, alicyclic, aromatic
aromatic hydrocarbons?
some or all of the C atoms are found in a benzene ring
alkynes?
contain at least one triple C to C bond
when there are 2 or more possible chains of the same length in a molecule?
the chain with the most branches is considered the longest chain
alcohol: pre and suffix?
prefix: hydroxy-
suffix: -ol
haloalkane prefix?
- chloro-
- bromo-
- iodo-
ester suffix?
-oate
acyl chloride FG, suffix?
- COCl
- -oyl chloride
amine functional group?
-NH2
amine pre, suffix?
pre: amino-
suff: -amine
nitrile FG?
-CN
Nitrile suffix?
-nitrile
-s of molecular formula?
- does not show how atoms are joined together
- diff molecules can have the same molecular formula
what must be included in the skeletal formula?
- functional groups
aldehydes are ketones w the same no. of Cs have the ?
same molecular formula, diff FGs
homolytic fission?
- each of the bonded atoms takes 1 of the e-s from the shared pair
- each atom now has an unpaired e-
- forms a radical
heterolytic fission?
- one of the bonded atoms takes both of the e-s from the bond
- the atom that takes both e-s becomes a - ion
- the atom that doesn’t take the e-s becomes a + ion
types of reaction?
addition, substitution, elimination
what happens in substitution?
an atom or group of atoms is replaced by a diff atom or gr of atoms (swap)
what happens in elimination?
involves the removal of a small molecule from a larger one. in an elimination reaction, one reactant molecule forms 2 products
