using resources

this shit HAAARRRDDD

Ceramics

A hard, brittle, heat-resistant, and corrosion-resistant material made by shaping and then firing an inorganic, non-metallic material like clay at high temperatures

soda lime glass

for windows & bottles

a mix of sand, sodium carbonate, and limestone - heated till it melts, cools to the shape we would like

has low melting point

Borosilicate glass

high(er) melting point - useful for objects used in heating i.e. kitchen &labware

made w/ sand & boron trioxide

composites

made by combining two different materials-

reinforcements: consists of the fibres/fragments of 1 material

matrix: surrounds the reinforcement

purification of water by distillation

1. Test the pH of the sample of water, to check if it is neutral(pH of 7)

2. if water is not neutral, then neutralize it.

3. set up the equipment- set up the conical flask on top of a tripod and gauze

4. The top of the conical flask should have a delivery tube pointed to a test tube.

5. test tube should be sitting in a beaker containing ice and water

6. gently heat the water in the flask using a Bunsen burner

7. the water will begin to evaporate, turning into steam which will pass through the delivery tube into the test tube

8. when the water is collected into the test tube, it cools down and condenses back into liquid water- distilled water

9. check pH is neutral at 7, using an universal indicator.

Treating Waste Water

Waste water is filtered with a large mesh or screen, to remove insoluble waste.

sewage is allowed to settle in large sedimentation tanks

produces liquid effluent and semi-solid sludge, which is taken away and digested by anaerobic bacteria.

air is bubbled through effluent, allowing aerobic bacteria to multiply and digest the organic molecules, as well as harmful bacteria

released into rivers etc as effluent

uses of ammonia

cleaning products

explosives

fertilisers

thermosoftening

soft/ melt on heating due to weak forces between chains — can change shape

thermosetting

do NOT soften/ melt on heating due to STRONG covalent bonds between chains (they burn)

factors that affect the polymer formed and its properties

lots of cross links

groups attached to the chains

conditions for production of ammonia by the Harbour process

temp-450 degrees C

pressure- 200 atmospheres

catalyst- iron

corrosion

metals become oxidised in the presence of water and oxygen

iron oxide

rust

rust

form of iron oxide Fe₂O₃.

it is loosely bonded in its structure.

called hydrated iron oxide

preventing corrosion

painting

coating in oil/grease

plastic covers

Sacrificial anodes

more reactive metals attached to a less reactive metal.

the more reactive metal corrodes first.

Galvanisation

A zinc coating is applied to an iron product

• zinc is more reactive than iron, and will oxidise rather than the iron

• this protects iron metal from corroding - this is called sacrificial protection

aluminium

the metal reacts with air, to form an aluminium oxide layer over the metal - this protects the metal from further corrosion (natural process)

Phyto mining

extracting metals using plants

• plants are grown on land containing the metal compounds that we want

• the plants absorb the metal compounds that we want, and they concentrate in their tissue

• the plants are harvested and burnt

• their ashes contain a relatively high concentration of the metal compound, which is mixed W/ sulphuric acid to make leachate

Leachate = a solution W/ contains dissolved copper ions

bioleaching

use of bacteria to extract metals

• Waste that contains a lot of metal/ a Low Grade ore = collected & bacteria added

• bacteria carry out chemical reactions to adsorb metal ions and produce leachate solution

Phyto mining & Bioleaching = why?

allows to economically extract metals from waste and/or low-grade ores, which is important as the earth’s resources are limited.

these methods do NOT involve digging, transporting, and disposing of large amounts of rocks - unlike traditional mining.

bronze

copper and tin

used for statues - not corrode easily

brass

copper and zinc

harder than copper, but can still be moulded into different shapes

used for door handles & musical instruments

steel

iron

carbon

other metals

high carbon = hard - used for cutting tools eg. chisel

low carbon = softer - used for car bodies

steel = rust - stainless steel = contain chromium and nickel

aluminium alloy

low density

used in aeroplane bodies

potable water

freshwater is used - rivers, reservoirs

passed through water beds to remove materials e.g. leaves and suspended particles

sterilised using chlorine gas, ozone, or UV light to kill microorganisms

NPK fertilisers

formulations of different salts

contain required elements in the percentages needed by the plants