Unit 3-Chemistry in Society Flashcards
What are the main properties of metals
Metals are malleable, they conduct electricity and they have a high melting point
What does oil rig stand for?
Oxidation is loss and reduction is gain
Describe metallic bonding
The atoms are held together by an electrostatic attraction between the positive nucleus and the delocalised electrons
What are rare earth metals used for?
Computers, laptops, mobiles, tablets and GPS
Name two rare earth metals
Neodymium and dysprosium
How do you break down metal ores which are below copper on the reactivity series?
You can break them down by heating them up
How do you break down the metal ores which are situated above mercury but below aluminium in the reactivity series?
By mixing them with carbon and then reacting them with oxygen
How do you break down the metal ores which are situated above zinc in the reactivity series?
By electrolysis
What is redox reaction
Redox reaction occurs when electrons are lost by one substance during oxidation and are gained by another substance during reduction
How can you predict the voltage output when two metals are connected together using an electrolyte?
By their position on the electrochemical series, the larger the gap, the larger the voltage output
In an electrochemical cell, what is used to connect the two solutions?
An iron bridge/salt bridge
In an electrochemical cell, what direction does the electrons flow?
The electrons flow from the metal electrode which is higher up in the electrochemical series to the metal electrode lower down in the electrochemical series. If both electrodes are the same element then the metal in the solution indicates the electron flow.
What is the difference between thermosoftening and thermosetting plastics?
Thermosoftening plastics soften when heat is applied
What is the definition of a non-biodegradable plastic
It doesn’t naturally break down
What happens when you burn a plastic?
Carbon monoxide is given off
What happens when you burn poly vinyl chlorine?
Hydrogen chloride is given off
What happens when you burn polyurethane?
Hydrogen cyanide is given off
Name two plastics and their uses
Kevlar-body armour
Poly(ethanol)- used in PVA glue
What are the two types of polymerisation?
Addition and condensation polymerisation
What is the polymer name of ethene?
Poly(ethene)
How do you identify if a polymer has been created through condensation or addition polymerisation?
If it’s a condensation polymer it will have oxygen in its main carbon chain
What is the repeating unit?
The part of a polymer which is repeated
What are monomers?
Monomers are small molecules which join together to form the polymer and normally are unsaturated
Name two natural polymers
Rubber and silk
What is a polyester?
A plastic formed by a carboxylic acid and an alcohol
What gets produced in condensation polymerisation?
Water
Where does the H20 come from in condensation polymerisation?
The OH comes from the alcohol and the O comes from the carboxylic acid
What two compounds are traditionally used when creating a polyester?
Diols and dicarboxylic acids
What is a novel material?
A material that doesn’t resemble anything that has previously been made
What is corrosion?
Corrosion is a chemical reaction which occurs on the surface of a metal
What happens during corrosion?
The metal element is reacting to form a metal compound
Rusting can only occur to which metal?
Iron
What conditions are needed for iron to rust?
Water and oxygen need to be present
What is used to test for rust?
Ferroxyl indicator, the yellow liquid will turn blue
What are smart materials?
Smart materials are compounds which can be changed through external stimuli
What is an alloy?
An alloy is a MIXTURE of metals which haven’t reacted together
What is brass made out of?
Copper and zinc
What is stainless steel made out of?
Iron and carbon
Why do we need fertilisers?
To replenish the soil with nutrients that the plants use to grow, which we can eventually feed on
What are the three main elements in fertilisers?
Nitrogen, Potassium and Phosphorus
Why is NPK in an ionic compound?
Because it needs to dissolve in water for the plants to absorb it
What can fertilisers cause by irresponsible usage?
Eutrophication and algal blooms
Describe the Haber process
Nitrogen and hydrogen are reacted and put in a compressor, the solution then moves into a catalyst chamber and then to a condenser. The ammonia is extracted and the recycled reactants are then put back into the catalyst chamber to reduce waste.
