Alkanes Flashcards
What type of molecules are alkanes?
Saturated hydrocarbons with single C-C bonds only
State the general formula for an alkane
CnH2n+2
Are alkanes polar or not?
Give a reason for your answer
No, there is no large difference in electronegativity between C and H
How are alkane hydrocarbons separated?
Fractional distillation
What is crude oil and how is it formed?
A fossil fuel formed from the breakdown of plants and animal remains
List the fractions in the fractional distillation column from high to low boiling point
Lubricating oils (340)
Fuel oils (300)
Diesel oil (250)
Kerosene (180)
Naptha (110)
Petrol (40)
Fuel gas (20)
What is fractional distillation and how does it work?
Separation of crude oil into different fractions according to their boiling points
Crude oil is vaporised in a furnace and passed into the bottom of a column
Temperature gradient( hot at bottom and cold at the top)
Vapour passes up the column and fractions condense at different heights
Why are alkanes cracked?
To convert longer chain hydrocarbons into shorter more valuable ones
What are the two types of cracking?
Thermal
Catalytic
What are the conditions for thermal cracking?
High temperature and high pressure
What are the conditions for catalytic cracking?
Low temperature and low pressure with a zeolite catalyst
What are the main products of catalytic cracking?
Motor fuels
Aromatic compounds
Cycloalkanes
Explain the economic reasons for cracking alkanes
What are the uses of alkanes?
What is fuel?
What is incomplete combustion and what products are formed?
Burning of alkenes with limited oxygen and produces carbon or carbon monoxide
What type of hydrocarbons are most likely to undergo incomplete combustion?
What is the equation for the combustion of propane?
State the environmental impact of CO
State the environmental impact of NO
State the environmental impact of C
What is the environmental impact of CO2?
What is the environmental impact of SO2?
What do catalytic converters do?
What are catalytic converters made of?
What do catalytic converters catalyse?
State the equation for this reaction
What is a flue gas?
State the two equations for desulfurising flue gases
What mechanism is the reaction of methane with chlorine?
What are the stages of free radical substitution?
Write equations for the reaction of methane chlorine
