Combustion of alkanes Flashcards
What does the complete combustion of alkanes produce?
Carbon dioxide and water
What does the incomplete combustion if alkanes produce?
Carbon monoxide and water
Combustion reacts give out…
heat
More heat is produced when the carbon chains are longer or shorter?
Longer
What are the two properties of a fuel?
They release heat energy when undergoing combustion
They store a large amount of energy in a small amount of weight
What are the 5 examples of an alkane fuel?
Methane Propane Butane Petrol Parraffin
What is bad about carbon monoxide?
It is a poisonous gas
When combustion takes place with a tiney tiny amount of oxygen, what is produced?
carbon (soot)
Incomplete combustion usually occurs with longer chain hydrocarbons. Why is this?
Because they need more oxygen to burn compared to shorter chains
What are the pollutants that combustion can produce?
Carbon monoxide Carbon dioxide Nitrogen oxide Sulfur dioxide Carbon particles Unburnt hydrocarbons Water vapour
What is bad about nitrogen oxides?
They react with water vapour and oxygen in the air to form nitric acid. Thus they contribute to acid rain and photochemical smog
How is nitric acid formed?
When there is enough energy for nitrogen and oxygen in the air to combine
What is bad about sulfur dioxide?
It combines with water vapour and oxygen in the air to create to form sulfuric acid. Thus it is a contributor to acid rain
How is sulfur dioxide formed?
It is produced when sulfur-containing impurities are present in crude oil
What is another name for carbon particles?
Particulates
What is bad about carbon particles?
They can worsen asthma and cause concer
What is bad about unburnt hydrocarbons?
They are greenhouse gases that contribute to photochemical smog which can cause a variety of health problems
What is bad about carbon dioxide?
It is a greenhouse gas which has contributed to global warming
What is bad about water vapour?
It is a greenhouse gas, so contributes to global warming
What is the name of the gases given out by power station?
flue gases
What is the name of the process of removing sulfur dioxide
Flue gas desulfurisation
How is the sulfur removed in flue gas desulfurisation?
A slurry of calcium oxide (lime) and water is sprayed into the flue gas which reacts with the calcium oxide and water to form calcium sulfite.
This is then oxidised to form calcium sulfate (gypsum)
What is gypsum used for?
To make plaster
What is an alternative to using calcium oxide?
Calcium carbonate (limestone)
All new cars with petrol engines must now all possess what?
Catalytic converters
What is the purpose of catalytic converters?
They reduce the output of carbon monoxide, nitrogen oxides, and unburnt hydrocarbons
What is the purpose of catalytic converters?
They reduce the output of carbon monoxide, nitrogen oxides, and unburnt hydrocarbons
What are the catalysts used inside a catalytic converter?
Platinum and rhodium
What is the shape of a catalytic converter?
It is a honeycomb structre
Why is the catalytic converter a honeycomb structure?
To provide a large surface area for the reactions to happen.
How does carbon dioxide contribute to global warming?
It traps infrared radiation so that the Earth’s atmosphere heats up
What is the name given to activities that produce no carbon dioxide emissions?
Carbon neutral
