C2a-e notes

Page 1

C2a - Structure Of Earth

Lithosphere - tectonic plates

- cold

- rigit

VOLCANOES

- molten rock (above surface)

- igneous

- lava (cools and forms igneous rocks)

- magma (molten rock below surface)

Plates move because ... convection currents - heat released from radio activity (move slowly)

continental slides under - more dense

C2b - Construction Materials

Rocks differ in hardness!

Limestone - sedimentary

Marble - metaphoric

Granite - igneous

C2c - Metals and Alloys

Copper - good conductor

- doesn't rust

- naturally occurs

reaction removes oxygen - reduction reaction

Electrolysis (reaction of electricity)

passes through - electrolyte

e.g copper sulphate solution purifies copper

Electrodes connect electrolytes

Positive electrode (anode) is impure copper

Negative electrode (cathode) is pure copper

Cathode increases in mass

- pure copper deposited

Cu2+ + 2 e- -> Cu (s)

(reduction reaction - ions gained)

C2d - Making cars

Rusting - iron + oxygen = oxidation reaction

- acid rain?

iron + oxygen + water = hydrated ion oxide

Aluminium (used in cars) - doesn't rust, less dense, lighter (better fuel economy)

Anode loses mass

- copper dissolves

Cu - 2 e- -> Cu2+

(oxidation reaction - atoms lose electrons)

ALLOY = MIXTURE OF METALS!

(smart alloys - nitinol can be bent)

C2e - making ammonia

Ammonia = Nh3 - alkine gas

Harber process

nitrogen +hydrogen = ammonia

N2 + 3H2 = 2NH3

(both reversible reactions)

- speeds up reaction

- reduces percentage yeild

- expensive too construct

- maintains high pressure

- low temperature increase yeild but slow reaction

- too expensive

- high pressure

- iron catalyst (high 200 pressure 450 temperature)

Catalyst - speeds reaction up

C2a

C2b

C2c

C2d

C2e