UNDERSTANDING METALS AND NON-METALS

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UNDERSTANDING METALS AND NON-METALS

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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) - PowerPoint PPT Presentation

Transcript of UNDERSTANDING METALS AND NON-METALS

Page 1: UNDERSTANDING   METALS  AND  NON-METALS

UNDERSTANDING METALS AND NON-METALS

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Fe + CuSO4

Cu + MgCl2

Cu + FeSO4

NO REACTION

4) Reaction of metals with solutions of other metal salts

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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.

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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

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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.

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(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

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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

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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

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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.

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Preliminary treatment(Ore is concentrated by removal of GANGUE)

Reduction (separation of oxygen from a compound)

Refining(Purification of impure metal.)

Washing Chemical separation

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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

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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

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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

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Extraction of AluminiumExtraction of Al involves two steps1) Concentration of ore2) Electrolytic reduction of alumina

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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

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Electrolytic Reduction of Alumina

At cathode : Al3+ + 3e-

At anode :2O2- - 4e-

AlO2

Alumina = Al2O3

Cryolite = AlF3.3NaF

Fluorspar = CaF2