Nomenclature and Isomerism Flashcards
What is an homologous series?
Family of chemicals
What must all chemicals in a homologous series be?
- Same functional group
- Similar chemical properties
- Each successive member differs by one carbon atom
What are alkenes general formula?
CnH2n+2
What is methane chemical formula?
CH4
What is ethanes chemical formula?
C2H6
What is propanes chemical formula?
C3H8
What’s butanes general formula?
C4H10
What are alkanes?
- Saturated (no multiple bonds
- Hydrocarbons
- Tetrahedral geometry
- Bond angle = 109.5 degrees
- Non-polar (similar electronegativities between C and H)
- Intermolecular forces are van der Waals
What is crude oil?
Complex mixture of many different hydrocarbons
What is factional distillation?
Separation of liquids depending on their boiling pint
Does the boiling point increase or decrease when chain length increases of alkanes?
Increase
What happens when the chain increase relating two the points of contacts between molecules?
More points of contacts
More Van der Waal’s forces
What are different types of reactions of alkanes?
- Combustion
- Cracking, isomerisation reformation
- Free radical substitution
What is the chain length for fuel gases?
1 to 4 Carbons
What is the chain length for gasoline/petrol?
5 to 12 carbons
What is the chain length for kerosene?
11 to 15 carbons
What is the chain length for diesel?
15 to 19 carbons
What are structural isomers?
Molecules with the same molecular formula but with different structural arrangements
How do you name alkenes?
- Determine the number of C atoms in the longest chain
- Number the chain so the substituent gets the lowest possible number
- Determine the number of C atoms in the side chain
- Make the name
What are cycloalkanes?
Cyclic hydrocarbons
Describe cycloalkanes:
- Carbons of the molecules are arranged in the form of a ring
- Are single bonded to each other
What are systematic nomenclature?
Names based on those of the parent alkanes
What does the stem show in systematic nomenclature?
Shows the number of carbon atoms in longest chain bearing the functional group
What does the suffix show in systematic nomenclature?
- The ending tells you which functional group is present
- If necessary, the position is annotated -2-
What does the prefix show in systematic nomenclature?
- If necessary, a prefix showing the position and identity of any substituents
- Side-chain names -appear in alphabetical order (butyl, ethyl, methyl, propyl)
- Numbers are separated from names by a hyphen –
- Numbers are separated from numbers by a comma ,
- If identical side-chains appear more than once prefix with di, tri, tetra etc