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Q 1 (a) Name one element, in
each case, to which the following descriptions could
apply:
(i) the molten metal which gives white fumes when
reacting with chlorine;
(ii) the burning metal which
combines directly with nitrogen;
(iii) the metal which
directly combines with sulphur on heating;
(iv) the
non-metal which forms two compounds when reacting with
chlorine.
Q 1 (b) Name the gas that
you can obtain in the laboratory from each of the following
and write the equation for the reaction taking place in each
case:
(i) ammonium nitrite;
(ii) ammonium
chloride;
(iii) ammonium nitrate.
Q 1(c) (i) Name the two
crystalline allotropes of sulphur. For each allotrope give a
sketch of the shape of its crystals.
(ii) Which sulphur allotrope is
stable at room temperature ?
Q 1(d) (i) What is the mass
of nitrogen in 1000 kg of Urea[CO(NH2)2]
?
(Answer correct to the
nearest kg.)
(H=1;C=12;N=14;O=16)
(ii) Is it possible to change the
temperature and pressure of a fixed mass of gas without
changing its volume ? Explain your answer.
Q 1(e) (i) What should be
the physical state of lead bromide if it is to conduct
electricity?
(ii) What
particles are present in pure lead
bromide?
(iii) Write the
equation for the reaction which take place at the electrodes
during the electrolysis of lead bromide.
Q 1(f)Three test-tubes
contain calcium nitrate solution , zinc nitrate solution and
lead nitrate solution respectively. Each solution is divided
into two portions (f) (i) and (f) (ii). Describe the effect of
:
(i) adding sodium
hydroxide solution to each portion in turn till it is in
excess.
(ii) adding ammonium
hydroxide to each portion in turn till it is in excess.
Q 1(g) State three tests by
which you could identify a gas as being chlorine.
Q
1(h) Define or explain the meaning of the
following terms :
(i) Molar
volume;
(ii) Fixation of
nitrogen;
(iii) Acid
salt;
(iv) Vulcanisation;
(v)
Ore.
Section -II(40
marks)
Answer any four
questions |
Q 2(a) (i) What is the purpose of the pH
scale?
(ii)
What is the pH of pure water?
(iii) A is a soluble acidic oxide; B
is a soluble base. Compared to the pH of pure water,
what will be the pH of :
(1) a solution of A
(2) a solution of
B?
Q 2(b) Taking sodium
carbonate as an example, give the meaning of the
following terms:
(i)
Water of crystallization;
(ii) anhydrous;
(iii) efflorescence.
Q 2(c) (i) Barium
chloride solution can be used to distinguish between a
sodium sulphate solution and a sodium nitrate solution.
How is this done?
(ii)
Write the equation for the action of heat on sodium
nitrate.
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