Presentation on theme: "Fe + CuSO 4 Cu + MgCl 2 Cu + FeSO 4 NO REACTION 4) Reaction of metals with solutions of other metal salts."— Presentation transcript:
Fe + CuSO 4 Cu + MgCl 2 Cu + FeSO 4 NO REACTION 4) Reaction of metals with solutions of other metal salts
Sodium (Na) Silver coloured that reacts with H 2 O so instantly that flames are produce due to formation of H 2 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 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) (Reactive) Naturally Occurring Other impurities Minerals – The naturally Occurring compounds of metals alongwith other impurities are known as minerals. Pure form Compounds Compounds of Metals
Minerals Profitably Conveniently Ores –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 The process used for
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, CaCl 2, MgCl 2 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 CaCl 2 At cathode :Ca e - At anode : 2Cl - - 2e - For MgCl 2 At cathode : Mg e - At anode : 2Cl - - 2e - Na Ca Cl 2 Mg Cl 2
ALUMINIUM Symbol : Al Colour : silvery white Atomic no (Z) : 13 EC :2,8,3 Valency : 3 Chief ore : Bauxite (Al 2 O 3.H 2 O) Bauxite contains 30% to 70% Al 2 O 3 and remaining is sand, silica (SiO 2 ), iron oxide (Fe 2 O 3 ) 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 150 o C,under pressure, for 4-5 hrs Al 2 O 3 (Amphoteric) Silica Iron oxide (basic in nature) b)NaAlO 2 C)2Al(OH) 3 2NaAlO 2 + H 2 O Sodium Aluminate Sodium silicate does not dissolve (removed by filtration) Al 2 O 3 + 3H 2 O NaOH + Al(OH) 3 (at 50 o C) + 2NaOH + NaOH + 2H 2 O
Electrolytic Reduction of Alumina At cathode : Al e - At anode :2O e - Al O2O2 Alumina = Al 2 O 3 Cryolite = AlF 3.3NaF Fluorspar = CaF 2