Combustion Flashcards
What is the word equation for a fuel cell?
Hydrogen + oxygen —> water
What is a fuel?
A chemical substance which stored energy can be transferred usefully to make things happen.
What ate petrol and diesel?
Fossil Fuels & Hydrocarbons
What is a hydrocarbon?
A substance with only carbon and hydrogen molecules.
What is the test for carbon dioxide?
Colourless limewater bubbles and turns cloudy/milky if carbon dioxide is present. If it’s not it stays colourless.
What is used to show the presence of water?
Cobalt chloride paper is used to show the presence of water. It is blue and turns pink if positive. Stays blue in negative.
What is the law of conservation of mass?
The idea of mass is never gained or lost in a chemical reaction. No new atoms are created or no atoms can disappear. Atoms are just rearranged to form a different substance.
What is oxidation?
Combustion reactions are exothermic what does this mean?
They release energy we can feel as heat.
What 3 things are needed for combustion - fire triangle?
Heat, fuel, oxygen
What does flammable mean?
Easily burns, spreads fire
What does oxidising mean?
Releases oxygen
What does explosive mean?
If heated or not handled correctly it can explode.
What is a fire extinguisher?
A fire extinguisher cools a fire by stopping oxygen getting to the fuel. It’s important you choose the correct type
What should you never use on an electrical fire?
Water because it conducts electricity and you can get a shock. You can use powder or carbon dioxide because it pushes the air containing oxygen away from the flames.
What should water also not be used on?
Water also shouldn’t be used on burning oil because it turns to steam and makes the fire spread out. However you can use foam or a fire blanket.
What is complete combustion?
When carbon burns in plenty of air and carbon dioxide is formed. It’s called complete because all the carbon reacts fully with oxygen.
What is incomplete combustion?
When there is not enough oxygen the carbon will undergo incomplete combustion.
Incomplete combustion causes what results?
Carbon dioxide gas
Carbon monoxide gas
Soot
What is a pollutant?
They can harm living things and damage the environment.
What causes acid rain?
Sulfur dioxide and nitrogen oxides are acidic gases that cause acid rain
Pollutants from vehicles can cause a harmful mixture of particles and gases what are these?
Carbon monoxide kills and id poisonous.
Carbon dioxide is linked to global. warming and climate change
Soot particles cause lunge damage + trigger asthma
What is a catalyst?
A substance that speeds up reactions but isn’t used up itself.
How do you control a pollutant?
Exhaust gases can reduce pollution, diesel vehicles have a filter to catch soot and others have catalytic converters
What is a catalytic converter?
It causes carbon monoxide gases to react with more oxygen to form carbon dioxide.
How does acidic rain get produced?
- Sulfur dioxide and nitrogen oxides from vehicles, power station and factories rise in the air
- The gasses dissolve in water vapour
- Rain is more acidic then normal
- Acid rains harm plants and people
