Need help memorising stuff.

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I dnt understand these fully:

1) Biofuels

2) Plant Oils & their uses

3) Changes in the Earth and its atmosphere

Thank yuee for any help :)

Posted: 07-06-12 13:46 by в

eg's of biofuels:

fast growing trees

manure and other waste- broken down by bacteria in a fermenter to produce biogas

corn or sugar cane- broken down by yeast in a fermenter to produce alcohol

bio-ethanol- used to fuel some cars.

Biogas cointains methene, which provides heat when it is burnt. biomass can be changed into biogas by fermentation. this is done by bacteria and yeast. usually the biomass is put inside a digester where bacteria and yeast break it down. 

( my class notes xD hope it helped) :D

Posted: 07-06-12 13:52 by priya777

ohhh kinda makes more sense thanx :)

Posted: 07-06-12 14:01 by в

no probies :D

Posted: 07-06-12 14:12 by priya777

-**-  :) <3

Posted: 07-06-12 16:18 by в

1.) Biofuels =  these are fuels which are produced from a renewable source like using manure and fermenting it to make biogas!! Or gettin rapeseed oil  and mixing it with ethanol etc... or gettin biodiesel as priya explained above

2.) Plant oils are used in cooking (vegetable oil XD ), burnin for energy, mix with a alcohol to produce a more cleaner combustion product etc etc.

3.) Changes in Earths atmosphere ==> went from high in CO2, SO2 (bad gases etc) due to volcanic eruptions to wot it is now due to CO2 causin the Earth to warm up (global warmin). Water vapour released by volcanoes condensed formin rivers and lakes. CO2 was able to dissolve into oceans etc reducing the amount of CO2 im the atmosphere. AS the temperature rose due to CO2 levels, this allowed single celled organisms like prokaryotes to thrive and also bacteria. They then evolved into plants which then tooke in CO2 to produce oxygen!! Thsi allowed more creatures to form etc. Then the CO2 levels decreased as some got aqbsorbed in seas, taken into plants and sedimented to form fossil fuels ==> which allowed a more stable climate to exist ... Hope i helped ***

Posted: 07-06-12 16:47 by Braniac

The best way to revise is to not do too much at once. When revising a diagram what you should do is get the diagram stare at it for let's say 10 seconds and then draw onto another blank sheet of paper what you remember. To remember formulas or meanings of things, write them down and read and read and read, treat it like you are trying to memorise a script. Listening to music while revising works as well. Your brain will associate different songs with different parts of the topic. Good luck! :)

Posted: 13-06-12 23:29 by Jade Longman