3.3.1 Intro to Organic Chem Flashcards
What is a hydrocarbon?
A compound consisting of hydrogen and carbon only
What does ‘‘saturated’’ mean?
Contain single carbon-carbon bonds only
What does ‘‘unsaturated’’ mean?
Contains C=C double bond
What does a molecular formula tell you?
The actual number of each type of atom
What does an empirical formula tell you?
The simplest whole number ratio of atoms of each element in a compound
What is a general formula?
Algebraic formula for a homologous series
What does the structural formual show you?
Shows the minimal detail that shows the arrangement of atoms in a molecule
What does the displayed formula show you?
All the covalent bonds and atoms present in a molecule
What does a skeletal formula show you?
The carbon skeleton and the associated functional groups of an organic compound
What is the order of priority for naming functional groups?
Carboxylic acids > aldehydes > keytones > alcohols > alkenes > halogenoalkanes
- Carboxylic Acids / Aldehydes / Keytones
- Alcohols
- Alkenes
- Haloalkanes
What are the differnet functional groups?
1) Alkanes
2) Alkenes
3) Alcohols - OH
4) Halogenoalkanes - Cl/Br/I
5) Aldehydes - COH
6) Ketones - CO
7) Carboxylic Acids - COOH
8) Esters - COO
What’s the shape around the carbon atom in saturated hydrocarbons?
Tetrahedral
What is a functional group?
An atom or group of atoms which, when present in different molecules, causes them to have similar chemical properties.
What is a homologous series?
Homologous series are families of organic compounds with the same functional group and the same general formula
➤ They show a gradual change in physical properties
➤ Each member differs by CH2 from the last
➤ Same Chemical Properties
What are the 5 first alkyl groups? General formula?
methyl
ethyl
propyl
butyl
pentyl
CnH2n+1
3 Rules of Syntax for Nomenclature
- Words are separated by numbers with dashes
- Numbers are separated by commas
- If there is more than one side chain, go in alphabetical order
How do you add a suffix? e.g for an alcohol, or alkene
- If the suffix begins with a vowel, e.g -ol, then remove an e.
- If it begins with a consonant, do not remove the e- from the stem.
Naming Alkenes - A Summary (4 points)
- Use the lower number of the two for the position of the double bond
- Names may include E or Z to show the type of stereoisomer
- If more than one double bond is present, suffix is diene or triene
- The suffix -en can go in front of other suffixes. e.g 2-bromobut-3-en-1-ol
Naming Halogenoalkanes - A Summary
- Use prefixes -fluoro -chloro -bromo -iodo
- Multiple side chains are listed in alphabetical order
- Low priority
Naming Alcohols - A Summary
- ending -ol
- position is between the name stem and the -ol
- higher priority than alkenes and haloalkanes
- becomes a hydroxy- if there’s another functional group with higher priority
Naming Aldehydes - A Summary
- Aldehydes are COH
- End in -al
- Always on the first carbon of the chain
- Very high priority
Naming Ketones - A Summary
- end in one
- only need the number position when there are 5Cs or more in a chain
Naming Carboxylic Acids - A Summary
- -oic acids
- Always at the end of the chain
- If there are carboxylic acids on both ends, it’s called a dioic acid
What are structural isomers?
Structural isomers have the same molecular formula but different structural formulae
What are the 3 types of structural isomerism?
- Chain isomerism
- Position isomerism
- Functional group isomerism
What are chain isomers?
Same molecular formula, different structures of the carbon skeleton such that it’s more branched
What are position isomers?
Compounds with the same molecular formula but with the same functional group positioned differently on the carbon skeleton
What are functional group isomers?
Compounds with the same molecular formula but with atoms arranged to give different functional groups
What are the matching pairs for functional group isomers?
- Aldehydes + Keytones
- Alkenes + Cycloalkanes
- Ester + Carboxylic ACids
What is reforming?
The formation of a cyclic compound, through the use of a platinum catalyst
What is the purpose of reforming?
The cyclic compounds are easier to burn, hence make better fuels.
Give the general equation for a reformation reaction
Alkane ➤ Cycloalkane + H2
What is stereoisomerism?
Stereoisomers have the same structural formulae but different spacial arrangement of atoms
Explain how E-Z isomers arise. MS [2]
➤ there is restricted rotation around the C=C double bond
➤ there are two different groups/atoms attached to both ends of the double bond
How do you identify the priority group in an e-z isomer?
The atom with the bigger atomic number
How do you name E-Z isomers?
- Determine the priority groups on both sides of the double bond
- If the priority atom is on the same size, it is labelled Z
- If the priority group is on the opposite site, it is labelled E
How does E-Z stereoisomerism effect physical properties?
They can have differing melting and boiling points.
For instance, depending on the position of certain electronegative atoms, it can actually make a molecule polar or non polar. Polar molecules have a higher melting point since IM forces are both VDW and permanent dipole dipole.
What is meant by heating under reflux? [2]
-Boiling a mixture
-And condensing / cooling the vapour to return it back to the reaction mixture
Each homologous series has its own general formula. State two other characteristics of an homologous series: MS [2]
-React in the same way since they are chemically similar
-Differ by CH2
-Have a trend in physical properties that gradually changes
Define saturated: MS [1]
Single bonds only
Explain how the Cahn-Ingold-Prelog (CIP) priority rules can be used to deduce the full IUPAC name of this compound. [6]
GOOGLE DOC
-Consider the groups joined to the right hand carbon of the C=C bond
-Consider the atomic number of the atoms attached
-C has a higher atomic number than H, therefore CH2OH has a higher priority than H
-Consider the groups joined to the left hand carbon of the C=C bond
-Both groups contain C atoms, so consider atoms one bond further away
-C from ethyl group has a higher atomic number than H from methyl group, so ethyl takes priority
-The highest priority groups, ethyl and CH2OH, are on the same side of the C=C bond so the isomer is Z
-Therefore, the name is Z-3-methylpent-2-en-1-ol
