3.3.2 alkanes Flashcards
(20 cards)
what are alkanes?
saturated hydrocarbons
define hydrocarbon
containing hydrogen, oxygen and carbon only
what is petroleum?
mixture of alkane hydrocarbons which can be separated by fractional distillation
what is cracking
breaking c-c bonds
Thermal cracking conditions?
high pressure (7000kPa) High temperature (400-900 Celsius)
Products of thermal cracking
alkenes (mainly) for polymers/ethanol.
hydrogen for haber/margarine
catalytic cracking conditions
low pressre
high temperature 450
zeolite catalyst
products of catalytic cracking
branched and cyclic alkanes
aromatic hydrocarbons
is combustion of alkanes exo/endo?
exothermic
what does internal combustion engine produce?
NOx, CO, C and unburned hydrocarbons
How are pollutants removed?
catalytic converters
Catalytic converters metals?
platinum, palladium, rhodium
Removal of CO/NO equation
2CO + 2NO = 2CO2 +N2
Removal of unburned hydrocarbons +No
= CO2 +N2 +9H20
flue gas desulphurisation equation
SO2 + CaO = CaSO3
conditions needed for alkane c-c bond to break
UV light
mechanism for alkane to halogenalkane?
free radical substitution
stages of FRS?
initiation propagation, termination
why is it called a chain reaction
continuing generating free radicals
why is FRS not really useful?
large variety of products possible.
