Improvements to Paper 2 Flashcards
What do you add the bromine to when testing for alkenes?
Add to the molecules!
Why is cracking useful
Products for fuels
short chain hydrocarbons more useful than long
products also used as starting material when making other compounds.
Word equation to make ammonia (Haber Process)
N2 + 3H2 —> 2NH3
What do NPK fertilisers contain?
Nitrogen, Phosphorus and Potassium
Why do NPK fertilisers contain the elements they do?
As it improves agricultural productivity, by helping plants grow larger and more rapidly.
Where are NPK fertilisers made? How?
Large industrial facilities using lots of raw materials processed together.
Give the equation for the production of NPK fertilisers
NH3 + HNO3 —> NH4NO3 (ammonium nitrate)
treating phosphate rock with nitric acid produces…
phosphoric acid and calcium nitrate
Instead of directly adding phosphorus to the plant, what must you do?
Neutralise it with ammonia
What is single superphosphate
A mixture of calcium phosphate and calcium sulfate which is used in NPK fertilisers
What is triple superphosphate?
Phosphoric acid and phosphate rock
What differences are there between the production in a lab vs industry
Lab uses dilute solutions so that they’re safe to work with. Whereas in industry ammonia is a gas and nitric acid is concentrated, and the reaction is strongly exothermic so heat is dangerous.
How do you make NPK fertilisers in a lab?
Crystallisation and titration. Crystallisation isn’t used in industry because it’s very slow.
How do you make NPK fertilisers in Industry
Carried out in giant vats at high concentrations.
Suggest a source of potassium in an NPK fertiliser
Potassium sulphate or chloride.
How are hydrogen and nitrogen produced for the haber process?
Nitrogen can be extracted from air
Hydrogen produced by reacting methane with steam.
What is the problem with a cool temperature?
It makes the reaction slow
What temperature is a compromise temperature?
450 c for a relatively fast rate of reaction and a high yield.
What catalyst is used in the haber process?
An iron catalyst.
What is the pressure used?
200 atmospheres.
What is the problem with high pressures?
Very expensive and dangerous
The catalyst has no effect at all on the…
no effect on the position of equilibrium
What is cracking?
The process where a large alkane is broken down to produce smaller more useful (flammable) molecules.
Describe conditions for catalytic cracking
Heat and a catalyst are used to speed up the reaction
Describe conditions for steam cracking
We use heat and steam.
Alkenes are …….. than alkanes
more reactive
What does the life cycle assessment do?
Attempts to put a number on the environmental impact of a product.
Name the 4 main stages of the life cycle assessment
impact of extracting the raw materials
manufacturing and packaging
using the product
product disposal
What are some problems with life cycle assessments?
The effect of some pollutants is hard to give a numerical value to.
Can be bias as can be written to deliberately support companies.
Describe life cycle of plastic bag
raw material;Crude Oil
manufacturing; cracking is used, so waste is reduced as other fractions have other uses
using; can be reused
disposal; not biodegradable and pollutes land.
Describe life cycle of a paper bag
Raw material; timber
manufacturing; processed using lots of energy= lots of waste
using; only used once
disposal; degradable, non-toxic, and can be recycled
Which 2 metals corrode much more than aluminium?
Iron and steel
Rust is only used for the corrosion of…
Iron
equation for the formation of hydrated iron oxide
iron + oxygen + water —> hydrated iron oxide
What 2 things are needed for iron to rust?
Water and air
What are 2 main ways to prevent rusting?
Barrier (e.g. painting, electroplating-electrolysis or oiling/greasing)
Sacrificial method which involves placing a more reactive metal such as zinc or magnesium to be reacted with instead
What is a ceramic?
A non-metal solid with a high melting point (not carbon-based)
Name 2 examples of ceramics
Glass and clay
What are composites?
A material made of one material EMBEDDED in another.
What two important things influence the properties of a polymer?
How and what it’s made from
Give a difference in properties between thermosetting and thermosoftening polymers
Thermosetting polymers don’t soften when heated whereas thermosoftening polymers do
What is potable water?
Water you can drink, it contains lots of other dissolved substances. (low levels)
What two processes are used when producing potable water via desalination
Reverse osmosis
Distillation
