C15(Using Our Resources) Flashcards
(45 cards)
What is rusting
The corrosion of iron
Oxygen and water are needed for iron to ..
Rust
How do you prevent rusting
Provide a barrier between iron and any oxygen and water
What is sacrificial protection
Attaching metals that are more reactive than iron on iron to stop it from rusting
Alloys are harder than pure metals because …
The regular layers in a pure metal are distorted by differently sized atoms in an alloy
How are steel alloys formed
Carefully controlled quantities of carbon and other elements are added to iron
What are the examples of steels
-high carbon steels- which are hard but brittle
-low carbon steels- which are softer and easily shaped
-stainless steels- which are resistant to corrosion
Monomers affect the properties of …
The polymers that they produce
Changing reaction conditions can …
Change the properties of the polymer that is produced
What are thermosoftening polymers
Polymers that will soften or melt easily when heated because their intermolecular forces are weak
What are thermosetting polymers
Polymers that do not soften because of their cross linking but will eventually char if heated very strongly
What is soda lime glass
made by heating a mixture of limestone, sand and sodium carbonate (soda) until it melts
What is borosilicate glass
made using sand and boron trioxide and has a higher melting point than soda-lime glass
What are clay ceramics
These are hardened materials that resist compressive forces
Polymers are …
-Poor conductors of heat and electricity
-Good insulators
What are composites
-Made from two components: reinforcement and matrix
-The reinforcement material is embedded in the matrix material which acts as a binder
The properties of composites depend on..
The reinforcement and matrix used
What are the reactants of the haber process
Hydrogen and nitrogen
What are the stages of the harber process
-H2 and N2 gases are pumped into the compressor through pipes
-The gases are compressed to about 200 atmospheres inside the compressor
-The pressurised gases are pumped into a tank containing layers of catalytic iron beads at a temperature of 450°C
-Unreacted H2 and N2 and product ammonia pass into a cooling tank.
-The ammonia is liquefied and removed to pressurised storage vessels
-The unreacted H2 and N2 gases are recycled back into the system
In the haber process the raw materials are…
-Readily available and inexpensive to purify
-Nitrogen —> from the air
-Hydrogen —> from natural gas
If the cost of extraction of raw materials is too high then …
The process is no longer economically viable
A higher temperature would favour …
Backward reaction as it is endothermic so a higher yield of reactants will be made
A lower temperature would favour …
Forward reaction as it is exothermic so higher yield of products will be made
A lower pressure will favour …
Backward reaction so a higher of reactants will be made
