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3. Group IIIA and Group IVA Elements eLearn.Punjab

EXERCISE

Q.1. Fill in the blanks.
i ) ______________________ acid has the chemical formula HBO2.
ii) Aluminium normally occurs as____________________ minerals found in
the rocks of outer portion of the earth.
iii) Aluminium gives ________________________gas with hot concentrated
H2SO4.
iv) Boron forms------------------------------------------- bond in its compounds.
v) The chemical formula of white lead is ___________________ .
vi) ___________________ is the only element with less than four electrons in
the outer most shell that is not a metal.
vii) In the Group IIIA of the periodic table,___________________ is a semi-
metal.
viii) Borax that occurs as a natural deposit, is called________________________.
ix) Cryolite is an important mineral of aluminium and its formula
is_____________________
x) A __________________________is a substance that has different resistances
to the passage of an electric current under different circumstances.

Q.2. Indicate True Or False
i) Boron always uses all the three of its valence eletrons for bonding purposes.
ii) Diaspore is an ore of carbon.
iii) Emerald is an ore of aluminium that has the chemical formula AlO3.2SiO2.
2H2O.
iv) An aqueous solution of borax is feebly acidic in nature.
v) In case of borax bead test, of cupric oxide, the beads are coloured blue in
the reducing flame.
vi) Boric acid can be titrated with sodium hydroxide.
vii) Carbon and silicon are the only non-metals in Group IVA.
viii) PbO is commonly known as litharge.
ix) Basic lead carbonate is a reddish brown pigment.
x) Aluminium oxide (Al2Q3) is also called bauxite.

Q. 4. What is the action of an aqueous solution of borax on litmus?
Q. 5. Give equations to represent the following reactions.

(a) Borax is heated with CoO
(b) Al2O3 is heated with NaOH solution

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