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UNDERSTANDING METALS AND NON-METALS. 4) Reaction of metals with solutions of other metal salts. Cu + FeSO 4. Fe + CuSO 4. NO REACTION. Cu + MgCl 2. Let us Study the Rx of Na (Metal) with Cl (Non metal). Sodium (Na)
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UNDERSTANDING METALS AND NON-METALS
4) Reaction of metals with solutions of other metal salts • Cu + FeSO4 Fe + CuSO4 • NO REACTION Cu + MgCl2
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 chloridewhich 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
1) Ionic compounds are solids & Hard Properties of ionic compounds 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.
MINERALS METALS (Reactive) (non reactive EgAu,Pt) Compounds Pure form Naturally Occurring Compounds of Metals Other impurities Minerals– The naturally Occurring compounds of metals alongwith other impurities are known as minerals.
ORES OM Minerals Conveniently Profitably 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.
Metallurgy : The process used for extraction of metals in their pure form from their ores is calledMetallurgy The process used for Extraction is called Metallurgy of metals in their pure form from their ores
Minerals:The naturally occurring compounds of metals along with other impurities are known as minerals Occurrence of metals 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) Refining (Purification of impure metal.) Reduction (separation of oxygen from a compound) Washing Chemical separation
Most reactive Reactivity series of metals :- Reactivity decreases 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 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 ieNaCl, 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- Na Cl2 Ca 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 Aluminium Extraction of Al involves two steps • Concentration of ore • 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 + 2NaOH Sodium Aluminate Sodium silicate + NaOH + NaOH does not dissolve (removed by filtration) NaOH + Al(OH)3 (at 50oC) + 2H2O Al2O3 + 3H2O
Electrolytic Reduction of Alumina Alumina = Al2O3 Cryolite = AlF3.3NaF Fluorspar = CaF2 At cathode : Al3+ + 3e- At anode :2O2- - 4e- Al O2