Reactions Flashcards
Addition of HX to alkene
Hydrohalogenation
No water present: H will react
Products: CO2 + H2O
Exothermic importance?
Combustion
Fossil fuels: transfers chem potential energy= heat energy
Thermal cracking
High pressures and temperatures without a catalyst
Addition of H2
Hydrogenation- addition
Dissolved in org. Solv. With Pt, Pd, No catalyst in an H2 atmosphere
Why are alkene more reactive than alkanes
Alkanes are unsaturated and can accept more atoms in their structure
Acid catalysed dehydration
Hearing of alcohol with excess of concentrated H2SO4 or H3PO4
Addition of halogen to alkene
Halogenation
Addition
Test for unsatration
Large hydrocarbon molecules into smaller ones + alkene
Cracking of hydrocarbons
Thermal cracking, catalytic cracking
Adddition of water to alkene
Hydration
Addition
Steam and a suitable catalyst eg H3PO4)
elimination HX from haloalkane
Dehydrohalogenation
Elimination: hot concentrated solution of NaOH or KOH in ethanol solvent without water)
Catalytic cracking
Lower temperatures and pressures in the presence of a catalyst
Alkanes to haloalkanes
Conditions
(Free radical halogenation)
In the presence of ultraviolet light or heat (for energy)
Substitution
Elimination of water from alcohol
Dehydration
Acid catalysed dehydration
Haloalkanes to alcohols
Conditions
Hydrolysis
Heat under reflux in a dilute alkali sol. (Catalyse reaction)
Substi.
Acid catalysed dehydration
Heating of alcohol was than excess of concentrated H2SO4 or H3PO4
