Combustion of Alkanes 2 Flashcards
What happens when sulfur burns in oxygen?
It forms sulfur dioxide
Where is sulfur found in fossil fuels?
Sulfur is present as an impurity in crude oil and other fossil fuels
How is sulfur trioxide (SO3) formed?
Sulfur dioxide can be further oxidised to sulfur trioxide
What happens when sulfur oxides dissolve in water?
They form acidic solutions, contributing to acid rain
What environmental problems are caused by sulfur dioxide and sulfur trioxide?
Thye contribute to acid rain, which damages vegetation, aquatic life and buildings
What causes acid rain?
Acid rain is caused by acidic non - metal oxides, such as sulfur oxides and nitrogen oxides, dissolving in rainwater
Why is rainwater naturally acidic?
Carbon monoxide dissolves in rainwater, forming weak carbonic acid
How do sulfur and nitrogen oxides make rain more acidic?
They dissolve in rainwater, forming stronger acids like sulfuric acid and nitric acid
What environmental impacts does acid rain have?
It damages trees, harming aquatic life and corrode buildings
How are sulfur dioxide emissions from petrol and diesel reduced?
Nearly all sulfur impurities are removed from the fuel before it is burnt
How are sulfur oxides removed from coal combustion waste genes?
Acidic sulfur oxides are removed from flue gases using bases like calcium oxide or calcium carbonate
What is the process of removing sulfur dioxide from flue gases called?
Flue gas desulfurization
How do power stations contribute to acid rain?
They burn fossil fuels containing sulfur compounds producing sulfur dioxide, which reacts with oxygen and water in the atmosphere to form sulfuric acid
What is flue gas desulfurisation?
It is the process of removing sulfur dioxide from power station flue gases to reduce acid rain
How does calcium oxide help in flue gas desulfurisation?
A slurry of calcium oxide and water is sprayed into flue gases, reacting with SO2, to form calcium sulfite
What is the wet scrubbing method for removing sulfur impurities from flue gases?
It involves forcing polluted gas through a pool of liquid containing calcium carbonate dissolved in water
What happens to calcium sulfite after flue gas desulfurisation?
It is further oxidised to calcium sulfate also known as gypsum
How does calcium carbonate help in wet scrubbing?
It neutralises the acidic sulfur dioxide gas and removes it from the flue gases
What is the product of the reaction between sulfur dioxide and limestone slurry?
Calcium sulfite precipitate
What alternative to limestone can be used in wet scrubbing?
Calcium oxide and water can be used instead
What is the final product when calcium oxide and water are used in wet scrubbing?
Gypsum which is used to make builders; plaster and plasterboard
