10th Class Chapter- Metals and Non-Metals
Metals
Metals are the solid materials
which are typically hard, malleable, ductile and conduct heat and electricity,
and also posses metallic lusture.
Example- Iron, Gold,
Aluminium, Silver, Copper etc.
Non-metals
Nonmetals are chemical
elements which lacks metallic properties. Non metals are either solids or gases
except Bromine (Br2), which occurs as liquid. Non-metals vaporizes
easily, insulator of heat and electricity. Non metals have high ionization
energy and elctronegativity values.
Example- Hydrogen, Helium,
Nitrogen, O2, F2, Ne, Cl, Ar, Kr, Xe, Rn, Br, C, P, S,
Se, I.
Exception in metals and non-metals
·
Mercury is liquid
at room temperature while other metals are solid.
·
Gallium and cesium
have very low M.P. while other metals have very high M.P.
·
Iodine is
non-metal but it has lusture (shiny).
·
Carbon
(Non-Metal) exist in different forms, and these forms are known as allotrope.
·
Graphite
(allotrope of carbon) conduct electricity and Diamond (allotrope of carbon)
having very high M.P. and B.P. is hardest natural substance known.
Chemical properties of metal
Burning of metals in air
Metals
burn in air ( as oxygen present in air) to produce metal oxide.
Metal + Oxygen -------> Metal Oxide
Example- 2Cu (Copper) + O2
(air) ---> 2CuO (Copper Oxide)
4Al (Aluminium) + 3O2
-------> 2Al2O3
(Aluminium Oxide)
·
Mostly metal
oxide are basic in nature but some metal oxide are amphoteric in nature i.e.
they show acidic as well as basic behavior like Aluminium Oxide, Zinc Oxide.
Al2O3
+ 6HCl -------> 2AlCl3 + 3H2O
Al2O3 + 2NaOH ----> 2NaAlO2 (Sodium Aluminate) + H2O
·
Mostly metal
oxide do not dissolve in water but some dissolve to form alkali.
Na2O
(s) + H2O (l) ---------> 2NaOH (aq)
K2O
(s) + H2O (l) ---------> 2KOH (aq)
·
Some metals prevent
further corrosion by making protective oxide layer on itself like Al, Zn, Pb
etc.
·
Some metals like
Na, K catches accidental fire so to prevent it, they are kept fully immersed in
kerosene oil.
Reaction of metals with water
Most metal react with water to form metal oxide and hydrogen gas.
Metal + Water -----> Metal Oxide + Hydrogen Gas
2K (s) + H2O (l)
-------> K2O (s) +
H2 (g)
Not all, but some metal oxide
react further with water to give metal hydroxide.
K2O (s) + H2O
(l) -----> 2KOH (aq)
Some metal do not react with
water like copper, lead, silver and gold.
Reaction of metals with acids
Most metal react with acids to produce salt and hydrogen gas.
Metal + Diluted Acid --------> Salt + Hydrogen Gas
2Al + 6HCl (dil) ---------> 2AlCl3 + 3H2
·
As HNO3
is strong oxidizing agent so, hydrogen gas not evolve when reaction take place
between metal and nitric acid Because HNO3 reduces itself to
nitrogen oxides (N2O, NO, and NO2).
·
Aqua-Regia (Royal
Water) is freshly prepared mixture of concentrated Hydrochloric Acid (Conc.
HCl) and concentrated Nitric Acid (Conc. HNO3) in the ratio of 3:1.
Aqua
Regia have great dissolving power, highly corrosive, fuming liquids. Aqua Regia
have ability to dissolve gold and platinum.
Reaction of metals with solution of other metal salts
More reactive metal have ability to displace less reactive metal from
their compounds in molten or solution form.
For example, If metal A is
more reactive then metal B then it displaces metal B from solution of metal B.
Metal A + Salt Solution of B
------> Salt Solution of A +
Metal B
Fe (s) + CuSO4 (aq)
-----> FeSO4 (aq)
+ Cu (s)