Alkanes Flashcards
What is condensed formula?
Formula split into structure based parts eg CH3CH2CH2CH3 = butane
What is a homologous series?
A series of organic compounds having the same functional group but with each successive member differing by CH2
What is a functional group?
A group of atoms responsible for characteristic reactions of a compound.
Alkanes don’t have a functional group
What is a structural isomer?
A compound with the same molecular formula but a different structured formula.
How do you show branches in condensed formula?
Put them in brackets
How do you form the basis of the name for skeletal?
Number of carbons in longest chain forms base of name. E.g 5 = ending in pentane.
How do you show branches in name of skeletal?
Number of carbon it is bonded at followed by a dash and what the branch is e.g 3-methyl pentane
How do you show other substances branching off?
Short line with substance at end.
E.g of name- 2-chloropropane
How do you include more than one branching off in the name?
e.g = 2,2-dimethylpropane
What occurs in for example, cyclopropane?
A bendy ‘banana bond’
What is it important to remember about cyclo alkanes?
2 less hydrodgens (CnH2n)
How is alkane volatility determined and why?
Fewer branches = lower volatility (higher boiling point) as higher surface contact area and therefore more induced dipole-dipole forces and more energy needed to break them.
Opposite for more branches.
What are the 3 stages of the radical substitution method?
Initiation
Propagation (growing)
Termination
Radicals:-
They have an unpaired electron and are very reactive because they want to pair up
Initiation stage:-
Cl—Cl –UV–> Cl• + Cl•
Homolytic fission
