Shared Flashcard Set

Details

AQA Science C1b Earth Oil and Atmosphere
Revision questions for the Core C1b Unit
33
Science
9th Grade
06/10/2009

Additional Science Flashcards

 


 

Cards

Term
Why is cracking of hydrocarbons so important?
Definition
We make smaller, more useful molecules from the bigger ones
Term
How is cracking carried out?
Definition
Heat strongly and pass over catalyst
Term
Alkenes are unsaturated hydrocarbons because they contain...............
Definition
......... A double bond
Term
Unsaturated hydrocarbons react with Bromine water. What happens and Why?
Definition
The bromine water is decolourised because the bromine reacts with the alkene to break the double bond
Term
Name 3 ways we use hydrocarbon-based fuels
Definition
Transport, heating, generating electricity
Term
What are the small molecules that make a polymer called?
Definition
Monomers
Term
Is ethene and alkene or alkane?
Definition
Alkene
Term
What is the general formula of a alkane?
Definition
CnH(2n+2)
Term
When monomers join together, the process is called........
Definition
..........addition polymerisation
Term
Name the polymer made from propene
Definition
polypropene (sometimes polypropylene)
Term
How are the atoms in polymer chains held together?
Definition
Strong covalent bonds
Term
The forces between polymer chains are called........
Definition
.....Intermolecular forces
Term
Describe the features of a thermsoftening plastic
Definition
Soften easily when heated as intermolecular forces are weak. Can be reshaped
Term
PET is a plastic used for pop bottles. Give three reasons for using it
Definition
1. Strong 2. Can be made see-through 3. Lightweight so cheaper to transport
Term
Give an example of a smart polymer and describe what it does
Definition
Shape memory polymer used as stitches in a wound. Body heat warms the polymer so it contracts pulling the skin edges together
Term
Word equation for photosynthesis
Definition
Water + Carbon dioxide ---> Glucose + Oxygen. Sunlight provides the energy
Term
Two ways to extract oils from plants and an example of each
Definition

Pressing - olives

Distillation - lavender oil

Term
Why are unsaturated vegetable oils usually liquids?
Definition
Because the double bonds stop the molecules fitting neatly together
Term
Liquid oils can be hardened by addition of hydrogen. What are the conditions for this process?
Definition
60 degrees Celsius and a Nickel Catalyst
Term
What does an emulsifier do?
Definition
Stops oil and water from separating
Term
Three examples of emulsions we eat/drink
Definition
Mayonnaise, Ice cream, Milk
Term
How are food additives identified on packaging?
Definition
E numbers
Term

Why do we use the following additives?

1. Colouring

2. Preservatives

3. Antioxidants

4. Emulsifiers

5. Acidity regulators

6. Flavourings

Definition

1. Improves appearance

2. Helps food keep longer

3. Stops food reacting with Oxygen

4. Improves texture

5. Controls pH

6. Changes the flavour

Term
What is Biodiesel?
Definition
Any fuel made from vegetable oils
Term
Why is ethanol made from sugar classed as a bio-fuel but if made from ethene is not?
Definition
Sugar is a natural plant source but ethene comes from cracking of crude oil which is a fossil fuel.
Term
Name the four main divisions of the Earth's structure
Definition

Outside --> Inside

Crust, Mantle, Outer core, Inner core

Term
Give another name for the Earth's crust
Definition
Lithosphere
Term
The theory of continental drift was put forward in 1915 by......
Definition
......Alfred Wegener.
Term
What makes the tectonic plates move?
Definition
Convection currents, in the mantle, caused by heating due to radioactive decay
Term
What was the main gas in the Earth's earliest atmosphere?
Definition
Carbon dioxide
Term
How was the Earth's earliest atmosphere formed?
Definition
Gases emitted by volcanoes
Term
Name the components of the atmsophere now and quote percentages
Definition

Nitrogen 78%

Oxygen 21%

Argon 0.9%

Carbon dioxide 0.04% (rising)

Other gases Trace%

Term
Why has the carbon dioxide level in the Earth's atmsophere risen so much in recent years?
Definition
Burning of fossil fuels
Supporting users have an ad free experience!