2 4) Reaction of metals with solutions of other metal salts Fe + CuSO4Cu + FeSO4Cu + MgCl2NO REACTION
3 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.
4 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
5 Properties of ionic compounds 1) Ionic compounds are solids & Hard2) They have high melting & boiling point3) They are generally brittle4) 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.
6 Other impurities MINERALS METALS Naturally Occurring (non reactive Eg Au,Pt)(Reactive)Pure formCompoundsNaturally OccurringCompounds of MetalsOther impuritiesMinerals – The naturally Occurring compounds of metalsalongwith other impurities are known as minerals.
7 OM Minerals Profitably Conveniently ORES Ores –The minerals from which metals are extracted Profitably & Conveniently are known as ores.Gangue – Ores contain metal compounds with some ofthe impurities like soil, sand and rocky materials etc. These impurities are known as gangue.
8 is called Metallurgy Extraction of metals in their pure form Metallurgy : The process used for extractionof metals in their pure form from their ores iscalled Metallurgyof metals in their pure formfrom their oresThe process used forExtractionis calledMetallurgy
9 Occurrence of metalsMinerals: The naturally occurring compounds of metals along with other impurities are known as mineralsOres: The minerals from which metals are extracted profitable & conveniently are called as oresGangue: 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.
10 Preliminary treatment (Ore is concentrated byremoval of GANGUE)Reduction(separation of oxygen from a compound)Refining(Purificationof impuremetal.)WashingChemical separation
11 Reactivity series of metals :- The arranging of metals in the decreasing order of their reactivity is called reactivity series of metals.K PotassiumNa - SodiumCa - CalciumMg - MagnesiumAl - AluminiumZn - ZincFe - IronPb - LeadCu - CopperHg - MercuryAg - SilverAu - GoldMost reactiveReactivity decreasesLeast reactive
12 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+ + 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-NaCl2CaCl2MgCl2
13 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
14 Extraction of Aluminium Extraction of Al involves two stepsConcentration of oreElectrolytic reduction of alumina
15 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+ 2NaOH2NaAlO2 + H2OSodium Aluminate+ NaOHSodium silicate+ NaOHdoes not dissolve (removed by filtration)+ 2H2ONaOH + Al(OH) (at 50oC)Al2O3 + 3H2O
16 Electrolytic Reduction of Alumina Alumina = Al2O3Cryolite = AlF3.3NaFFluorspar = CaF2At cathode : Al e-At anode :2O e-AlO2
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