Gasses in the Atmosphere Flashcards
(14 cards)
Percentage composition of air
- Nitrogen 78%
- Oxygen 21%
- Argon 0.9%
- Carbon Dioxide 0.04%
Are combustion reactions exothermic or endothermic?
Exothermic
Magnesium observations with oxygen
- Intense white flame
- White powder produced (magnesium oxide)
Hydrogen observations with oxygen
- Exothermic
- Water is produced
Hydrogen observations with oxygen
- Blue flame
- Colourless, poisonous gas produced
What are conduction reactions classified as?
Oxidation Reactions
What is thermal decomposition?
Thermal decomposition is the term used to describe reactions where a substance breaks down due to the action of heat.
Thermal decomposition metal carbonate general formula
metal carbonate → metal oxide + carbon dioxide
What colour is copper (II) carbonate and copper oxide?
Copper(II) carbonate is a green powder and slowly darkens as black copper(II) oxide is produced.
How to test which metal carbonate reacts fastest
The carbon dioxide given off can be tested by passing the gas through limewater and looking for which metal carbonate turns milky the fastest.
State three greenhouse gasses
- Carbon dioxide
- Methane
- Water vapour
What is the greenhouse effect?
- Short wavelength radiation (ultraviolet radiation) is emitted from the sun
- When it strikes the earth’s surface, some of it is absorbed and some is re-emitted from the surface of the Earth as long wavelength radiation (infrared radiation)
- Much of the radiation is trapped inside the Earth’s atmosphere by greenhouse gases which can absorb and store the energy
Sources of carbon dioxide
- Combustion of wood and fossil fuels
- Respiration of plants and animals
- Thermal decomposition of carbonate rocks
- The effect of acids on carbonates
Explain why an increasing amount of carbon dioxide in the atmosphere is likely to cause a problem for the environment.
- Carbon dioxide is a greenhouse gas
- That causes climate change / global warming
- Melting of polar icecaps / flooding / wildfires/ sea levels rising
