cracking Flashcards
what are the 2 types of cracking
thermal cracking
catalytic cracking
what 3 products are formed by catalytic cracking
- aromatic compounds
- branched alkanes
- cycloalkanes
why are branched alkanes and cycloalkanes used in cars
the burn more efficiently in the internal combustion engine of a car
if the products catalytic cracking decolourise bromine solution what does this show the product contains
alkenes
what type of catalyst does catalytic cracking use and what is it made up of
a zeolite catalyst
made up of silicon dioxide and aluminium oxide
what structure do zeolite catalysts have
honeycomb structure
large SA
what temperature is needed for catalytic cracking
720K
what pressure is needed for catalytic cracking
pressure higher than atmospheric
what temperature is needed for thermal cracking
700-1200 K
what pressure is needed for thermal cracking
7000kPa
what products does thermal cracking form
forms an alkene and an alkane
what happens when the c-c is broken during thermal cracking
breaks causing 1 electron from the pair in a covalent bond to go to each of the carbon atom
2 chains produced end in carbon atom with unpaired e- (these are called FREE RADICALS, these are highly reactive)
