Ceramaics, polymers and composites/ NPK fertilisers Flashcards
What are ceramics?
non-metal solids with high melting points that aren’t made from carbon-based compounds
How are ceramics made?
by shaping wet clay and then heating it in a furnance
Why is clay hard hut but brittle?
include the type of bonds it contains
because it is a mixture of compounds containing both ionic and covalent bonds and when it goes from wet to dry in the furnace a regular crystilla structure is produced where the atoms and compounds are held together by strong bonds throughout the ceramic
What are the properties of clay?
- hard
- Brittle
- electric insulators
- resistant to corrosion
What are the two types of glass?
soda-lime and Borosilicate
How is soda- lime glass made?
by heating a mixture of sand, sodium carbonate and limestone unitl it melts then let it cool
How is Borosilicate made?
made from sand and boron trioxide
it melts at higher temeratures than soda lime glass
what is Borosilicate used to make?
chemical glassware, cooking equipment and car headlights
What are composite materials?
materials that consist of two materials with different properties
the materials are combined together to produce a material that ahs its own improved properties
Describe the structure of a composite material?
fibres or fragments of a material (aka reinforcement) are surrounded by a matrix acting as a binder
What to the properties of polymers depend on?
What monomers they are made from and the condition under which they ere made in
How is low-density poly(ethene) produced from ethene?
the moderate temperature under high pressure with a catalyst
flexible
used for bags and bottles
How is high-density poly(ethene) produced from ethene?
produced at a lower temperature and pressure with a different catalyst
more rigid and used for water tanks and drain pipe
Describe what are thermosoftening polymers
- melt when they are heated
- polymer chains have weak intermolecular forces between them
Describe what are thermosetting polymers
do not melt when they are heate
polymer chains are connected to each other by strong covalent bonds called cross-links, holding the chains together in a solid structure
- dont soften when they’re heated.
strong, hard and rigid
Why do we need fertilisers?
because when plants are harvested for food, the minerals aren’t replenishable
also these minerals are used up by plants as they grow
Why are fertilisers better than manure to fertilise fields?
- more widely available
- easier to use
- don’t smell
- have enough of each nutrient so more crops can be grown
What are NPKs
formulations of various salts that are mixed together to give the appropriate percentage of each element
What can ammonia be used for?
to manufacture ammonium salts and nitric salts
mainly used in the production of fertilisers to increase the nitrogen content of the soil
what’s the word equation to make ammonium nitrate
Ammonia + nitric acid = ammonium nitrate
Ammonia can be produced to produce ….
nitric acid
Ammonia can neutralise _____ to produce _____
nitric acid
ammonium nitrate
Why are nitrogen-based fertilisers important?
because they increase the yield of the crops
What can be used as a source of potassium and why?
potassium chloride and potassium sulphate because they are soluble
Phosphate rock contains high levels of phosphorous compounds.
why arent they directly used as a fertiliser?
the compounds are insoluble
How are soluble phosphates made?
by reacting phosphate rock with acids
What happens when phosphate rock is reacted with nitric acid?
phosphoric acid and calcium nitrate
Phosphoric acid is then neutralised with ammonia to produce ammonium phosphate
What happens when phosphate rock is reacted with sulfuric acid?
calcium sulfate and calcium phosphate
aka single superphosphate
What happens when phosphate rock is reacted with phosphoric acid?
calcium phosphate ( triple superphosphate)
