Metallurgy
1. Write a brief note on the physical properties of non – metals.
The physical properties of non – metals are –
1. They are either solids or gases except bromine which is a liquid.
2. They usually have low density.
3. They are bad or poor conductors of heat and electricity, except graphite, which is a
good conductor.
4. They are non-lustrous (dull), except graphite and iodine.
5. They are non-malleable and brittle.
6. They have low melting and boiling point except graphite.
7. They are non – ductile.
8. They are non – sonorous.
9. They have low tensile strength.
10. They are soft except diamond, which is hard.
2. Distinguish between metals and non metals based on the (a) formation of oxides, (b)
action on acids, (c) action on hydrogen, (d) action on chlorine.
S. No Properties Metals Non – Metals
1. Formation of Form basic oxides Form acidic oxides
oxides
2.
Action of acids Dissolve in acids and Generally do not dissolve in
produce hydrogen gas acids
3.
Action on
hydrogen Generally do not combine Combine with hydrogen and
with hydrogen, however Na, form stable hydride.
Ca, Li form volatile hydride.
Form chlorides which are
Action on Form chlorides which are generally hydrolysed by
4. chlorine generally not hydrolysed by water.
water.
, 3. Explain the chemical properties of metals.
Chemical properties of metals are –
1. Action of oxygen on metals: Metals generally combine with oxygen to from oxides,
which are basic in nature.
2 Zn + O2 2 ZnO
Zinc oxide
2 Mg + O2 2 Mg O
Magnesium oxide
2. Action with water on metals: Metals on reaction with water form metal oxide or
metal hydroxide and liberate hydrogen gas.
(i) Sodium and potassium react vigorously with cold water forming their hydroxides and
liberating H2 gas.
2 Na + 2 H2O 2 NaOH + H2
2 K + 2 H2O 2 KOH + H2
(ii) Magnesium on reaction with water form magnesium oxide and hydrogen.
Mg + H2O Mg O + H2
(iii) Heated iron reacts with steam to give ferroso ferric oxide and hydrogen.
3 Fe + 4 H2O Fe3 O4 + 4 H2
(iv) Metals like Au, Ag and Cu do not react even with steam.
3. Action of acids on metals: Many metals react with dilute acids and liberate hydrogen
gas.
2 Na + 2 HCl 2 NaCl + H2
Mg + H2SO4 MgSO4 + H2
Fe + 2 HCl FeCl2 + H2
Metals like Cu and Ag do not release hydrogen from dilute acids.
4. Reaction with Halogens: Metals react directly with halogens like chloride to form
electrovalent compounds which have the properties of salts.
2 Na + Cl2 2 NaCl
Ca + Cl2 CaCl2
1. Write a brief note on the physical properties of non – metals.
The physical properties of non – metals are –
1. They are either solids or gases except bromine which is a liquid.
2. They usually have low density.
3. They are bad or poor conductors of heat and electricity, except graphite, which is a
good conductor.
4. They are non-lustrous (dull), except graphite and iodine.
5. They are non-malleable and brittle.
6. They have low melting and boiling point except graphite.
7. They are non – ductile.
8. They are non – sonorous.
9. They have low tensile strength.
10. They are soft except diamond, which is hard.
2. Distinguish between metals and non metals based on the (a) formation of oxides, (b)
action on acids, (c) action on hydrogen, (d) action on chlorine.
S. No Properties Metals Non – Metals
1. Formation of Form basic oxides Form acidic oxides
oxides
2.
Action of acids Dissolve in acids and Generally do not dissolve in
produce hydrogen gas acids
3.
Action on
hydrogen Generally do not combine Combine with hydrogen and
with hydrogen, however Na, form stable hydride.
Ca, Li form volatile hydride.
Form chlorides which are
Action on Form chlorides which are generally hydrolysed by
4. chlorine generally not hydrolysed by water.
water.
, 3. Explain the chemical properties of metals.
Chemical properties of metals are –
1. Action of oxygen on metals: Metals generally combine with oxygen to from oxides,
which are basic in nature.
2 Zn + O2 2 ZnO
Zinc oxide
2 Mg + O2 2 Mg O
Magnesium oxide
2. Action with water on metals: Metals on reaction with water form metal oxide or
metal hydroxide and liberate hydrogen gas.
(i) Sodium and potassium react vigorously with cold water forming their hydroxides and
liberating H2 gas.
2 Na + 2 H2O 2 NaOH + H2
2 K + 2 H2O 2 KOH + H2
(ii) Magnesium on reaction with water form magnesium oxide and hydrogen.
Mg + H2O Mg O + H2
(iii) Heated iron reacts with steam to give ferroso ferric oxide and hydrogen.
3 Fe + 4 H2O Fe3 O4 + 4 H2
(iv) Metals like Au, Ag and Cu do not react even with steam.
3. Action of acids on metals: Many metals react with dilute acids and liberate hydrogen
gas.
2 Na + 2 HCl 2 NaCl + H2
Mg + H2SO4 MgSO4 + H2
Fe + 2 HCl FeCl2 + H2
Metals like Cu and Ag do not release hydrogen from dilute acids.
4. Reaction with Halogens: Metals react directly with halogens like chloride to form
electrovalent compounds which have the properties of salts.
2 Na + Cl2 2 NaCl
Ca + Cl2 CaCl2
