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.

Other impurities MINERALS METALS Naturally Occurring (non reactive Eg Au,Pt) (Reactive) Pure form Compounds Naturally Occurring Compounds of Metals Other impurities Minerals – The naturally Occurring compounds of metals alongwith other impurities are known as minerals.

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 of the impurities like soil, sand and rocky materials etc. These impurities are known as gangue.

is called Metallurgy Extraction of metals in their pure form Metallurgy : The process used for extraction of metals in their pure form from their ores is called Metallurgy of metals in their pure form from their ores The process used for Extraction 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 Most reactive Reactivity decreases 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+ + 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 + 2NaOH 2NaAlO2 + H2O Sodium Aluminate + NaOH Sodium silicate + NaOH does not dissolve (removed by filtration) + 2H2O NaOH + Al(OH)3 (at 50oC) Al2O3 + 3H2O

Electrolytic Reduction of Alumina Alumina = Al2O3 Cryolite = AlF3.3NaF Fluorspar = CaF2 At cathode : Al3+ + 3e- At anode :2O2- - 4e- Al O2