reactivity series

most reactive metal

Group 1 and group 2, Al

Medium reactive metal

Zn,Fe,Pb

Least reactive metal

Cu,Ag,Au

most reactive metal are extracted by

electrolysis of molten

medium reactive metal are extracted by

by carbon

least reactive metal

found uncombined in native

least reactive metal never

react with acids

extraction of metals

Al and Fe ore

Al ore

Bauxite Al2O3

Fe ore

hematite Fe2O3

Al is extracted by electrolysis of

molten bauxite

molten bauxite dissolves in

cryolite

to reduce melting point from C2000 to 900

to increase electrical conductivity

why do we use cryolite as an electrolyte

reduction ionic equation

Al3+ + 3e → Al

oxidation ionic equation

2O2- → O2 + 4e

Fe2,CO,CO2,O2

waste gases from the extraction of Al

graphite

both cathode and anode are made of

cryolite equation

2F- → F2+2e

anode electrode should be replaced each while since it reacts with

C + O2 → CO2

low density 2.7g/cm³, strong, malleable

Al is used extensively in the manufacture of aircraft

Since Al is coated with a non-porous layer of Al2O3 and has low density

al is used to make food containers

to strengthen the Al cables

Al electricity cables have a steel core

Al reacts very slowly

because al is coated with non-prous layer of Al2O3 which protects Al

Cable is made of

Copper

Overhead cable is made of

Al

low density and conducts electricity

why do we use Al to make overhead cables

blast furnance

we use it for extraction of Fe

as fuel

to produce the reducing agent CO

why do we use coke

to remove impurities by forming slag

Why do we use limestone

Cao + sio2 → casio3

Symbol equation for forming slag

Calcium oxide + silicon dioxide → calcium silicate

Word equation for forming slag

CaO + SiO2 → CaSiO3

nuetralisation reaction to occur in the blast furnace

to make roads and cement

Give 2 uses of slag

N2 and CO2

waste gases produced from blast furnance

hot air

enters blast furnace

limestone,hematite,Coke

enters blast furnace

low density

slag is

lower density than molten cast iron

slag floats over molten cast iron because

Fe2O3 + 3CO → 2Fe + 3Co2

write a symbol equation for reducing hematite in the blast furnace

C + O2 → CO2 + heat

write the symbol equation for the source of heat in the blast furnace

C + O2 → CO2 + heat

write the exothermic reaction which is the source of heat in the blast furnace

C + O2 → CO2 + heat

then we add excess coke

CO2 + C → 2CO

How does the reducing agent CO is formed in the blast furnace

Basic oxygen furnace

we use __ to convert cast iron to steel

hematite to molten cast iron

Blast furnace

molten cast iron to steel

Basic oxygen furnance

using basic furnace, blowing jet oxygen in the molten cast iron. C and S react with oxygen gas to form gases CO, CO2, SO2 escape. Si meet with oxygen to form SiO2. Then we add CaO to remove SiO2 by forming slag

how can you convert cast iron into steel

cast iron, low carbon steel, medium carbon steel, high carbon steel.

the kind of steels produced by Basic oxygen furnace

pipes

cast iron

ships

low carbon steel

car bodies

medium carbon steel

tanks

high carbon steel

A mixture of 2 metals or metal and non metal are melted then mixed together

define alloys

Cu + Zn

Brass

Cu + Tn

bronze

Fe + Ni + Cr

stainless steel

Fe + C

steel

As the big atoms stops the small one from slipping

explain why alloys are not malleable

alloys are electrically conductive

true

alloys are a compound

false

alloys are a mixture

true

alloys have a chemical formula

false

to improve the quality for a particular job

why do we use alloys

to make cuttery

to make chemical plants

food containers

sinks

uses of stainless steel

pink brown

Copper Solid

Copper aq

blue

Copper oxide solid

black

CuSo4 hydrated

blue

CuSo4 anydrous

white

the corrosion of iron

define rusting

water and oxygen

the two substances required for rust to occur

red/brown flakes

describe the appearance of the iron after rusting

to displace the volume of reacted oxygen

why does the water rise up the tube

since iron is not in contact with the water

if the water contained salt then no effect

galvanizing

prevent iron from rusting - 1

plating

prevent iron from rusting - 2

prevent iron from rusting - 3

cathodic protection

prevent iron from rusting - 4

sacrificial protection

prevent iron from rusting - 5

painting

coating iron by a layer of zinc

Galvanism

since Zn is more reactive than Fe

Zn will corrode instead of Fe

explain by mentioning ions and electrons, why the exposed steel does not rust

Zn → Zn+2 +2e

Galvanizing equation

Fe → Fe3+ + 3e

Plating equation

cathodic protection requires

battery is required and Fe is connected to cathode

the metal connected to Fe must be mire reactive than Fe as Zn is more reactive than Fe hence Zn will corrode instead.

the metal in sacraficial protection has to be