Module 4, Section 1 Flashcards
Define homologous series.
A series of organic compounds with the same functional group, but with each successive member differing by -CH2
What is heterolytic fission?
Bond breaks unevenly, one of the bonded atoms receives both electrons from the bonded pair. X-Y = X+ + Y-
What is homolytic fission?
Bond breaks evenly and each bonded atom receives on electron from the bonded pair. Radicals are formed, unpaired electrons
How does chain length affect boiling point?
As chain length increases, molecule have larger surface areas, so more surface contact possible, greater London forces, more energy required
How does branching affect boiling point?
Fewer surface points of contact between branched alkane molecules, fewer London forces, branching gets in the way, prevents molecules getting as close together
What happens in the free radical substitution of chlorine and methane?
1) Initiation: Cl2 with UV light = 2Cl.
2) Propagation: CH4 + Cl. = .CH3 + HCl
.CH3 + Cl2 = CH3Cl + Cl.
3) Termination: Cl. + .Cl = Cl2
Cl. + CH3 = CH3Cl
.CH3 + .CH3 = C2H6
When is stereoisomerism satisfied?
2 double-bonded carbon atoms each have two different atoms/groups.
What must be done if all groups are different?
Assign priority according to atomic number.
Higher priority=higher atomic number
What naming system is used if carbon atoms have at least one group in common?
‘cis’ and ‘trans’
Describe a substitution reaction of an alkane
Alkane + OH- = alcohol + Br-
Describe an elimination reaction of an alkane
Alcohol + acid catalyst = Alkene + H2O
Describe hydrogenation of an alkene
H2, Ni catalyst, 150 degrees celsius
Alkene = Alkane
Describe hydration of an alkene
H2O(g), 300 degrees celsius, 60-70 atm, solid phsophoric(V) acid catalyst eg H3PO4
Alkene = Alcohol
Describe halogenation of an alkene
Alkene + hydrogen halide = Haloalkane
