Chapter 12 Flashcards
Alkanes and cycloalkanes are
saturated hydrocarbons
alkane
saturated hydrocarbon containing single c-c bonds only
alkane general formula
CnH2n+2
polarity of alkane bonds
alkane bonds are non polar as carbon and hydrogen have similar en values
shape of alkanes
tetrahedral, 109.5
electrons repel eachother as far apart as possible VSEPR
sigma bond
overlap of atomic orbitals directly between the bonding atons
two electrons shared
where is sigma bond placed
positioned on a line directly between bonding atoms
when are alkanes extracted
during fractional distillation
boiling point trend
as chain length increases so does boiling point
why does chain length increase boiling point
larger sa so more surface contact
greater london forces so more energy to overcome
effect of branching on bp
fewer surface points of contact- less ldf
molecules cant get close eachother leading to weaker ldfs, less energy
BOILING POINT DECREASES
boiling point of:
pentane
2-methyl-butane
2,2-dimethyl propane
36
28
9
solubility of alkanes
alkanes are insoluble because hydrogen bonds in water are stronger than its london forces
they prefer to interact with one another
reactivity of alkanes
very unreactive
alkane reactions
combustion and halogenation
carbon monoxide
alkane incomplete combustion
fuel + oxygen ->carbon monoxide + water
soot/carbon
incomplete combustion equation
fuel+ less oxygen->soot+ water
Which type of hydrocarbon are most likely to undergo incomplete combustion?
longer chains
environmental effect of carbon monoxide and soot
co- toxic/poisonous
c-asthma, cancer, global dimming
