S4 - Chemistry Test (2) Flashcards
What are polymers?
Giant molecules formed when lots of small molecules join together
How are alkene monomers made?
By cracking long-chain alkanes
What are the properties of poly(ethene) and what is it used for?
- Cheap
- Strong
- Plastic bags and bottles
What are the properties of poly(propane) and what is it used for?
- Strong
- High elasticity
- Crates and ropes
What are the properties of poly(chloroethene) and what is it used for?
- Rigid
- Building materials: drain pipes & insulating wiring
What properties to polymers generally have?
- Light
- Don’t break
- Don’t rot
- Don’t conduct electricity
- Thermoplastic - can be melted and made into other shapes
- Thermoset - will not melt after forming
What are alloys?
Metals and some non-metals mixed together
What are the properties of stainless steel and what elements is it made up of?
- Strong & resists corrosion
- Iron & Chromium
What are the properties of Duralumin and what elements is it made up of?
- Strong & low density
- Aluminium, copper & magnesium
What elements do plants need?
Nitrogen, Potassium & Phosphorus
What are the 2 types of fertilisers?
Natural & synthetic
What are examples of natural fertilisers?
Compost or manure
What are synthetic fertilisers?
Ionic compounds that contain either N, P or K
What property does a good fertiliser have and why?
- Soluble in water
- So it can be absorbed through the roots
What is ammonia and is it soluble?
A colourless gas with a pungent smell.
Yes.
What solution does ammonia give?
An alkaline solution
What is the Haber process and when was it developed?
It converts nitrogen and hydrogen gas into ammonia.
Early 20th century.
What is the Ostwald process?
The production of nitric acid by catalytic oxidation of ammonia
What is the catalyst used in the Ostwald process?
Platinum
Why do atoms become radioactive?
Because their nuclei are unstable