UNDERSTANDING METALS AND NON-METALS
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Transcript of UNDERSTANDING METALS AND NON-METALS
UNDERSTANDING METALS AND NON-METALS
Fe + CuSO4
Cu + MgCl2
Cu + FeSO4
NO REACTION
4) Reaction of metals with solutions of other metal salts
Sodium (Na)Silver coloured that reacts with H2O so instantly that flames are produce due to formation of H2 gas.
Let us Study the Rx of Na (Metal) with Cl (Non metal)
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.
Chlorine(Cl)Non-metal which is Greenish Colour & very poisonous.
Formation of sodium Chloride
Ionic BondsThe bond which are formed by give & take of electrons are called as ionic or electrovalent bonds.
Ionic CompoundsThe 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) (Reactive)
Naturally Occurring
Other impuritiesMinerals – The naturally Occurring compounds of metals
alongwith other impurities are known as minerals.
Pure form Compounds
Compounds of Metals
Minerals
Profitably ConvenientlyOres –The minerals from which metals are extracted Profitably & Conveniently are known as
ores.
OM
Gangue – Ores contain metal compounds with some of the impurities like soil, sand and rocky materials etc.
These impurities are known as gangue.
ORES
of metals in their pure form from their ores
Extraction
Metallurgyis called
The process used for
METALLURGY : The process used for extractionof metals in their pure form from their ores is called Metallurgy
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)
Reduction (separation of oxygen from a compound)
Refining(Purification of impure metal.)
Washing 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 Na - Sodium Ca - Calcium Mg - Magnesium Al - Aluminium Zn - Zinc Fe - Iron Pb - Lead Cu - Copper Hg - Mercury Ag - Silver Au - Gold
Reactivity decreases
Most reactive
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 chloridesOn eletrolysis• metals are deposited at cathode and• Chlorine is liberated at anodeFor NaCl• At cathode : Na+ + e-
• At anode :2Cl- - 2e- For CaCl2
• At cathode :Ca2+ + 2e-
• At anode : 2Cl- - 2e-
For MgCl2
• At cathode : Mg2+ + 2e-
• At anode : 2Cl- - 2e-
Na
Ca
Cl2
Cl2
Mg
Cl2
ALUMINIUM• 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 AluminiumExtraction of Al involves two steps1) Concentration of ore2) 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
(Amphoteric)
• Silica
• Iron oxide
(basic in nature)b) NaAlO2
C) 2Al(OH)3
2NaAlO2 + H2O
Sodium Aluminate
Sodium silicate
does not dissolve (removed by filtration)
Al2O3 + 3H2O
NaOH + Al(OH)3 (at 50oC)
+ 2NaOH
+ NaOH
+ NaOH
+ 2H2O
Electrolytic Reduction of Alumina
At cathode : Al3+ + 3e-
At anode :2O2- - 4e-
AlO2
Alumina = Al2O3
Cryolite = AlF3.3NaF
Fluorspar = CaF2