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AQA
AQA Chemisty 1b
15
Chemistry
Not Applicable
05/20/2008

Additional Chemistry Flashcards

 


 

Cards

Term

Cracking

Definition

Splitting up long-chain hydrocarbons. It is a thermal decomposition reation- breaking molecules down by heating them with a catalyst. Aluminium oxide is the catalyst used.

Term

Alkenes

 

Definition
Alkenes are hydrocarbons which have a double bond between two of the carbon atoms in their chain.
Term

Alkenes and Polymerisation

Definition

This means joining together lots of small alkene molecules to form very large moecules. These long-chain molecules are called polymers.

Term
Polymers
Definition

Polymers have different physical properties. The physical properties of a polymer depend on what it is made from. The polymer's physical properties are also affected by the temperature and pressure of polymerisation.

Term

Extract Oils from plants

Definition
Some fruits and seeds contain lots of oils e.g. Avocados and Olives, Brazil Nuts, peanuts. These oils can be extracted and used for food/ fuel.
Term

Vegetable Oils

Definition
They provide a lot of energy. There are other nutrients in oils such as oils from seeds such as  oils containing vitamin E.
Term

Emulsions

Definition

Emulsions can be made form oil and water. They are thicker than oil or water: e.g. mayonnaise and vinegar.

Term
Emulsions II
Definition

You can mix an oil with water to MAKE an emulsion. Emulsions are made up of lots of droplets of one liquid suspended in another.

Term

BioDiesel

Definition
Biodiesel comes from plant crops which can be harvested every year. You can always keep making Biodiesel and it is made by distilling crude oil.
Term

BioDiesel II

Definition

It is biodegradable and its less toxic than regular diesel. It is expensive and difficult to make enough and replace.

Term
Unsaturated Oils
Definition
Unsaturated oils contain long-chain molecules with lots of carbon atoms. They contain double bonds between some of the carbon atoms in their carbon chains.
Term
Unsaturated Oils II
Definition
Unsaturated vegetable oils are liquid at room temperature. They can be hardened by reacting with hydrogen in the prescence of a nickel catalyst. This is called hydrogenation.
Term
Food Additives
Definition

Addotoves are used to preserve food and to make it look or taste different to the original. Most additives in the UK had E-numbers in.

Term
Food Additives II
Definition
Preservatives help food stay fresh. COlourings and flavourings make food look and taste better. Emulsifyers and stabilisers stop emulsions from separating out.
Term
The Evolution of the atmosphere
Definition

The Earth's surface was originally moltern for many millions of years. It was so hot that any atmosphere just 'boiled away' into space. Eventually things cooled down a bit and a thin crust formed but volcanoes kept erupting. The volcanoes gave out lots of gas- including CO2, water vapour and nitrogen. The early atmosphere was mostly CO2 with virtually no O2. The oceans formed when the water vapour condensed.

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