C5 - The Earths reasources and Chemical Analysis Flashcards
what percent of the worlds atmosphere is nitrogen
78%
what percent of the worlds atmosphere is oxygen
21%
what percent of the worlds atmosphere is water vapour
<1%
what percent of the worlds atmosphere is carbon dioxide
<1%
what percent of the worlds atmosphere is argon
<1%
name three greenhouse gases
- methane
- carbon dioxide
- water
what gases are believed to have been released from volcanoes during the first billion years
- carbon dioxide
- nitrogen
- water vapour
- ammonia
there are theories about the earths early atmosphere have changed over time. why?
there is little evidence left as earth formed 4.6 billion years ago
what are the effects of polar ice caps melting
rising sea levels which leads to less land avalable for housing
what are the effects of warming seas
coral reefs dying which leads to reduction in aquatic biodiversity
what are the effetcs of more frequent and extreme wether events
- global food shortage
- risk to human life
exaplain how the interaction between short and long wavelenth interaction with matter creates the greenhouse effect
- short wavelength radiation from the sun is absorbed by the earth
- the earth re-emits longer wavelength radiation which is absorbed and reflected back to earth by greenhouse gases
what are human activites that increase green house gases in the atmosphere
methane:
- cattle farming
- landfill
- rice plantations
carbon dioxide:
- burning fossil fuels
- deforestation
what is pure water
solely made up of H2O molecules, all partilces are the same
what is potable water
Water that is safe for humans to drink
what is a finite reasource
A finite resource is one which will eventually run out as it is being used up at a faster rate than it can be replaced.
what is an renewable reasource
Renewable resources are ones which are not going to run out
what is the test for hydrogen
Test gas with a lighted splint.
Observation: A lighted splint “pops”.
Reason: Hydrogen burns rapidly - the “pop” is a small explosion.
what is the test for carbon dioxide
Bubble gas through limewater.
Observation: Limewater turns cloudy/milky.
Reason: Insoluble calcium carbonate is formed.
what is the test for oxygen
Test gas with a glowing splint.
Observation: A glowing splint re-lights.
Reason: The concentration of oxygen is mugh higher than in air so the splint can re-light.
what is the test for chlorine
Test with damp blue litmus paper.
Observation: Litmus paper goes white (it is bleached)
Reason: Chlorine is a bleach
in chromatography what is a stationary phase
- Does not move
- Attracts certain chemicals
- Usually paper
in chormatography what is a mobile phase
- Does move
- Chemicals must be soluble in it
- Often water
how do we calculate the Rf value
Rf = distance travelled by component / distance travelled by solvent
what is a mixture
contains different particles
what is an element
substance only made from one type of atom
what is a compound
Substance made from different types of atoms joined together
how do we know if a substance is pure
- Pure substances have fixed melting and boiling points eg. pure water melts at 0 °C and boils at 100 °C.
-Pure substances always have a fixed, single melting and boiling point.
how do we know if a substance is impure
Impure substances melt and boil over a range of temperatures
what is a formulation
Many consumer products are not pure substances. They are a carefully designed mixture of substances known as a formulation.
