Give an example of a substance that is cracked and the products that it makes.
Decane (10 carbons) is cracked to produce octane (8 carbons) and ethene (2 carbons).
The burning of fossil fuels is causing a rise in the level of carbon dioxide in the atmosphere. How is this affecting the oceans and the climate?
Due to the greenhouse effect the climate is warming, the polar ice caps are melting and sea levels are rising. The oceans are also becomimg more acidic as more CO2 dissolve.
Why might polymers become expensive in the future?
They are made from crude oil and crude oil is running out.
What happens when you react unsaturated oils with hydrogen.
They become saturated oils.
Name the two main gases that make up the Earth's atmosphere today.
Nitrogen - 78%
Oxygen - 21%
Give three factors which might affect the properties of a polymer.
The length of the polymer chains.
The degree of branching in the polymer chains.
The degree of cross linking between the polymer chains.
Why do some foods contain partially hydrogenated vegatable oil rather than butter.
Since they are only PARTIALLY hydrogenated the are still unsaturated. Unsaturated oils are healthier than saturated fats.
When ethene is hydrated with steam what substance is formed?
What kind of carbon-carbon bond do alkenes have?
What is cracking and why is it done?
Breaking down long chain hydrocarbons to produce smaller molecules. We have more of the long chain hydrocarbons than we need and not enough of the smaller molecules that are used in petrol.
What are polymers and what kind of substances are made form polymers?
They are long chain moecules with a repeating structure. Polymers are used to make plastics.
Give one reason why Alfred Wegener's theory of continental drift wasn't accepted for a long time.
He could not give a mechanism through which the continents could be made to move. We now know that convection currents in the mantle cause the crust to move.
List 4 uses of polymers.
What is the general formula for alkenes?
What is an emulsion?
A mixture of oil and water bound together by an emulsifier.
What kind of carbon-carbon bond do unsaturated oils contain?
Draw the chemical structure of ethene.