Fuels and Hydrocarbons Flashcards
Nature's Chemistry Plastics - Chemistry in Society
What is a fuel?
A fuel is a substance that produces energy when burnt.
What is combustion?
Combustion is another word for burning. It is n exothermic reaction that gives out heat.
What three things are required to keep a fire going?
Oxygen, heat, fuel.
What are the three main sources of fuel?
Coal, crude oil [oil] and gas.
What is a finite source?
A finite source is something that runs out with time.
How is coal formed?
300 million years ago, giant plants died in swamps. Over millions of years these plants were buried under water and dirt. Heat and pressure turned the dead plants into coal.
How is crude oil and gas formed?
Around 400 million years ago, tiny sea plants and animals died and were buried on the ocean floor. Over time, they were covered by sand and silt rocks. The heat and pressure turned them into crude oil and gas. Today we drill down through the layers of sand and silt rocks to reach the oil and gas.
What are hydrocarbons made of?
Hydrogen and carbon.
What do hydrocarbons produce when they react with oxygen?
Carbon Dioxide and water.
What is the test for carbon dioxide?
It turns lime water milky/cloudy.
What is the test for water?
It turns blue cobalt chloride paper pink.
Pollution Problems - When is carbon monoxide formed?
It is formed when there is not enough oxygen to burn the hydrocarbons completely. It is toxic, but it is odorless and colourless.
Pollution Problems - When is soot formed?
Incomplete combustion causes soot particles. It is black and can cause breathing difficulties, asthma and even cancer.
How can you reduce pollution?
1) Removing sulphur from fuels.
2) Adding a transition metal [platinum/rhodium] catalytic converter to engines, which changes toxic emissions into harmless gases.
How is crude oil separated?
Fractional distillation.
