Burning Fuels
Combustion is the scientific word for ______.
burning
When a substance is oxidised, it reacts with which element?
oxygen
What are the three sides to the fire triangle?
heat, fuel and oxygen
What is meant by pollution?
a substance that harms the environment or living things
Most of the energy that warms the Earth's surface comes from here
What is the Sun?
Define the word 'fuel'.
a substance that contains stored energy that can be transferred to make things happen
During complete combustion, carbon reacts with oxygen to form an oxide. What is the name of the oxide?
carbon dioxide
Describe how the oxidising hazard symbol looks.
It has an O with flames on the top.
What kind of reaction occurs if there is not enough oxygen for complete combustion?
Incomplete combustion
Melting icecaps and glaciers, changed weather patterns colder winters and warmer summers, and rising sea levels are all examples of this.
What is climate change?
What is the word equation for a combustion reaction with a metal?
Metal + Oxygen -> Metaloxide
Write the word equation for the oxidation of iron.
iron + oxygen → iron oxide
Why is a combustion reaction exothermic?
It is a reaction in which energy is transferred to the surroundings.
State two products of incomplete combustion.
Any from: soot, carbon monoxide, carbon dioxide
An increase in the greenhouse effect, resulting in an increase in the Earth's surface temperature
What is meant by global warming?
Write the word equation for the combustion of hydrocarbons with oxygen AND describe how you would test for both products.
hydrogen + carbon + oxygen → carbon dioxide + water
Limewater will go cloudy in the presence of carbon dioxide.
Cobalt chloride paper will go pink in the presence of water.
This law states that the mass of reactants must equal the mass of the products formed.
What is "the law of conservation of mass"?
Use the fire triangle to explain why carbon dioxide puts out an electrical fire.
The carbon dioxide smothers the fire, excluding oxygen. Oxygen is one of the three factors needed for a fire, so the fire is put out.
What is acid rain and how is it caused?
a rain that is more acidic than usual because it contains dissolved sulfur dioxide
The warming of the Earth's surface as a result of trapping energy from the sun by greenhouse gases in the atmosphere
What is the greenhouse effect?
If you touch bubbles that are full of hydrogen with a lighted splint, they burst into flames. The flames continue when the lighted splint is removed and then go out. Explain these observations.
Hydrogen is a fuel. When it is in contact with oxygen, the flame from the splint causes the hydrogen to react with the oxygen, creating flames. A good answer will also say that the flames continue after the splint is removed and will last until all the hydrogen has reacted. Then the flame goes out.
Until 1772, many scientists thought substances contained phlogiston, which was lost when a substance was burned. This accounted for the loss in mass. Why was this theory wrong?
Mass is not lost. When substances burn they combine with oxygen to produce carbon dioxide and water. If all of the gases are contained, the mass of the reactants will equal the mass of the products.
Explain why an oil fire should not be treated with a water-filled fire extinguisher.
Water will turn to gas explosively, spreading droplets of burning oil and spreading the fire.
Explain why vehicle engines produce nitrogen oxides.
Nitrogen and oxygen from the air react together in the hot temperature inside the engine.
Explain how human activity could be causing global warming.
We release carbon dioxide when we burn fossil fuels. As we burn more fossil fuels, more carbon dioxide is released. Carbon dioxide is a greenhouse gas so it absorbs energy radiated from the Earth's surface and transfers it back. More carbon dioxide increases this effect, so the Earth will get warmer.