Download Sub: Science - Vakharia Academy

UNDERSTANDING
METALS AND NON-METALS
4) Reaction of metals with solutions
of other metal salts
Fe + CuSO4
Cu + FeSO4
Cu + MgCl2
NO REACTION
Let us Study the Rx of Na (Metal) with Cl (Non metal)
Sodium (Na)
Silver coloured that reacts with H2O so
instantly that flames are produce due to
formation of H2 gas.
Chlorine(Cl)
Non-metal which is Greenish Colour & very
poisonous.
But, when these two dangerous substances chemically combine,
they form a compound known as Sodium chloride which is so
safe that we eat it everyday.
Formation of sodium Chloride
Ionic Bonds
The bond which are formed by give & take of electrons are
called as ionic or electrovalent bonds.
Ionic Compounds
The compounds formed by the transfer of electrons are
known as ionic compound
Properties of ionic compounds
1) Ionic compounds are solids & Hard
2) They have high melting & boiling point
3) They are generally brittle
4) Generally, they are soluble in water but insoluble in
organic solvents like kerosene, petrol etc.
5) They do not Conduct electricity in solid state but their
aqueous or molten form conducts electricity.
(non reactive Eg Au,Pt)
Pure form
(Reactive)
Compounds
Naturally Occurring
Compounds of Metals
Other impurities
Minerals
– The naturally Occurring compounds of metals
alongwith other impurities are known as
minerals.
ORES
Minerals
Profitably
OM
Conveniently
Ores –The minerals from which metals are
extracted Profitably & Conveniently are known as
ores.
Gangue – Ores contain metal compounds with some of
the impurities like soil, sand and rocky materials etc.
These impurities are known as
gangue.
The process used for extraction
of metals in their pure form from their ores is
called Metallurgy
The process used for
of metals in their pure form
from their ores
Occurrence of metals
Minerals: The naturally occurring compounds of metals
along with other impurities are known as minerals
Ores: The minerals from which metals are extracted
profitable & conveniently are called as ores
Gangue: The impurities like soil, sand, rocky materials
etc which are present in ores are called gangue.
Metallurgy: The process used for extraction of metals in
their pure form their ores is known as metallurgy.
Preliminary treatment
(Ore is concentrated by
removal of GANGUE)
Washing
Reduction
(separation of
oxygen from a
compound)
Refining
(Purification
of impure
metal.)
Chemical separation
Reactivity series of metals :The arranging of metals in the decreasing order of their reactivity is
called reactivity series of metals.
K - Potassium
Most reactive
Na - Sodium
Ca - Calcium
Mg - Magnesium
Al - Aluminium
Zn - Zinc
Reactivity decreases
Fe - Iron
Pb - Lead
Cu - Copper
Hg - Mercury
Ag - Silver
Au - Gold
Least reactive
Extraction of Metals of High Reactivity
• K, Na, Ca, Mg, Al etc show high reactivity.
• Na, Ca and Mg occur in the form of metal chloride ie NaCl, CaCl2, MgCl2
• They are obtained by electrolysis of their molten chlorides
On eletrolysis
• metals are deposited at cathode and
• Chlorine is liberated at anode
For NaCl
• At cathode : Na+ + eNa
• At anode :2Cl- - 2eCl2
For CaCl2
Ca
• At cathode :Ca2+ + 2eCl2
• At anode : 2Cl- - 2eFor MgCl2
• At cathode : Mg2+ + 2eMg
• At anode : 2Cl- - 2eCl2
ALUMINIUM
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Symbol : Al
Colour : silvery white
Atomic no (Z) : 13
EC :2,8,3
Valency : 3
Chief ore : Bauxite (Al2O3.H2O)
Bauxite contains
30% to 70% Al2O3 and remaining is sand, silica (SiO2),
iron oxide (Fe2O3) etc
Extraction of Aluminium
Extraction of Al involves two steps
1) Concentration of ore
2) Electrolytic reduction of alumina
Step 1: Concentration of ore (or) Bayer’s process
a) Bauxite + aq caustic soda
Condition=heat at 140 to 150oC,under pressure, for 4-5 hrs
• Al2O3 + 2NaOH
(Amphoteric)
• Silica + NaOH
• Iron oxide + NaOH
2NaAlO2 + H2O
Sodium Aluminate
Sodium silicate
does not dissolve (removed by filtration)
(basic in nature)
b) NaAlO2 + 2H2O
C) 2Al(OH)3
NaOH + Al(OH)3
Al2O3 + 3H2O
(at 50oC)
Electrolytic Reduction of Alumina
Alumina = Al2O3
Cryolite = AlF3.3NaF
Fluorspar = CaF2
At cathode : Al3+ + 3eAt anode :2O2- - 4e-
Al
O2