Unit 2- Nature’s Chemistry Flashcards
Prefixes (No. of carbons in a hydrocarbon chain)
1- Meth…
2- Eth…
3- Prop…
4- But…
5- Pent…
6- Hex…
7- Hept…
8- Oct…
Homologous series definition?
A family of compounds with the same general formula and similar chemical properties.
Alkanes’ key points?
Always end in ANE.
Contain C-C single bonds only.
Described as saturated molecules.
General formula for alkanes?
CnH2n+2
Alkenes’ key points?
Always end in ENE.
Always contain at least one C=C double bond.
Can be described as unsaturated molecules.
General formula for alkenes?
CnH2n
Rule for naming alkenes?
Number the carbon atoms from the end that gives the carbon of the double bond the lower number.
Isomer key points?
Isomers are compounds which have the same number of atoms of each kind but differ in the way in which these atoms are arranged.
Isomers have the same molecular formula but different structural formulae.
Isomers have different physical properties including melting and boiling points.
What is a straight chain hydrocarbon?
In a straight chain hydrocarbon, all the carbon atoms in the molecule are linked one after the other in a single continuous chain.
What is a branched chained hydrocarbon?
In a branched chained hydrocarbon, the molecule has one or more side chains of carbon atoms coming out from the main chain.
Rules for naming branched chained alkanes?
- Identify the longest chain of carbon atoms and name the alkane with this number of carbon atoms.
- Identify the branch and name it according to the number of carbon atoms in the branch.
- Number the branch so that it has the lower of two possible numbers.
Types of branches in branches chained hydrocarbons?
Methyl branch- One carbon atom in the branch- CH3
Ethyl branch- Two carbon atoms in the branch- C2H5
Propyl branch- Three carbon atoms in the branch- C3H7
Side chain prefixes?
Di (2 branches)
Tri (3 branches)
Tetra (4 branches)
Branches are named in alphabetical order so ethyl will always come before methyl.
Rules for naming branched chained alkenes?
The same rules as used for naming alkanes, however for alkenes, the position of the double bond must be identified.
The number for the position (the lowest possible) is placed before the -ene.
When naming a branched alkene, the position of the double bond is more important than the position of the branch.
What are cycloalkanes?
A homologous series of hydrocarbons with cyclic shapes.
What do the names of cycloalkanes start and end with?
The names of cycloalkanes start with CYCLO and end with ANE.
What type of bonds do cycloalkanes contain?
C-C single bonds.
Are cycloalkanes saturated or unsaturated molecules?
Saturated
What is the general formula for cycloalkanes?
CnH2n
Which is the most reactive out of alkanes, alkenes and cycloalkanes?
Alkenes