03 Atmosphere And 04 Oxygen Flashcards
What are the four main gases in our atmosphere and what percentage are they?
Nitrogen - 78%
Oxygen- 21%
Carbon dioxide- 0.04%
Argon - 0.9%
What are the four ways in which carbon dioxide have decreased in our atmosphere?
- Used as a reactant in photosynthesis.
- Trapped in fossil fuels
- CO2 dissolved into the oceans. Formed carbonate rocks through the CO2 reacting with metal oxides.
- formed rocks
Why have oxygen levels increased in the atmosphere?
Product of photosynthesis
Levels of oxygen in the atmosphere therefore steadily rose.
Why have water vapour levels decreased?
-Temperature of the earth decreased.
- Water vapour condensed to form oceans
Why have levels of nitrogen increased in the atmosphere?
Nitrogen is a very stable element, therefore built up in the atmosphere
What is the word equation for the phosphorus experiment?
Phosphorus + Oxygen —> Phosphorus oxide
What is fractional distillation?
Technique used to separate the different components of the mixture of liquids. It relies upon the different liquids, having different boiling points
What are the steps of fractional distillation of air?
- Air is cooled to 200 degrees and the solid carbon dioxide and water is removed.
- The liquid is fed into the bottom of the fractionating column which is warmer at the bottom than the top.
- The temperature at the bottom of the column is higher than the boiling point of nitrogen so nitrogen boils, and rises to the top of the column and is piped off as a gas at the top.
- Oxygen and argon have higher boiling points, so they remain as liquids and are taken out at the bottom of the column.
What is a use for oxygen?
Life support
What is a use for nitrogen?
Food storage
What is a use for Carbon dioxide?
Fizzy drinks
What is use for argon?
Light bulbs
Is oxygen a reactive gas?
Yes
When do oxides form?
When an element reacts with oxygen
Oxygen reaction word equation
Rhgchhrb + Oxygen —> dghdgug oxide
What is the difference between metal oxides and non metal oxides?
Metal - basic
Non natal- acidic
What happens when iron reacts with oxygen?
It sparks like fireworks and is an alkaline
What happens when carbon reacts with oxygen?
It burns and forms and odourless gas. It is acidic.
What happens when magnesium reacts with oxygen?
It burns the bright, white light and white powder forms
What happens when oxygen reacts with sulphur?
It burns blue flame and a colourless gas forms. It is acidic.
What happens when oxygen reacts with sodium?
It burns with a bright yellow flame, and it’s an alkaline solution
What are the three components of the fire triangle?
Heat oxygen and fuel
What is the word equation for complete combustion?
Fuel + oxygen —> Carbon dioxide + water
What is complete combustion?
Enough oxygen to burn the fuel completely
