8/2/2019 Sec 4 Chemistry Practice
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Sec 4/5 Practice
Chemistry
1(a) Which compound has the lowest melting point? Explain with
reference to the
bonding why it has a low melting point. [3]
(b) Why does aluminium oxide have a high melting point? Explain
briefly. [2]
(c) After sulfur dioxide is dissolved into a beaker of water, is
it likely to react with
sodium hydroxide, hydrochloric acid, sodium chloride or
potassium sulfate? Choose
one compound only. [1]
(d) Draw the dot and cross diagram of the oxide of chlorine,
Cl2O. Draw only the
outermost electrons. Note that oxygen atom is the central atom.
[2]
2. Thallium, Tl, is a white metal in Group III of the Periodic
Table.
(a) What is the formula of thallium(III) sulfate?
(b) Calculate the Mr (relative formula mass) of the compound in
(a).
(c) How many moles is there in a dose of 1 g of the compound in
(a)? [4]
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Time : 45 min
8/2/2019 Sec 4 Chemistry Practice
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( b) Airplanes need to be made of a metal that is lightand
fairly strong.
Which metal is more suitable to be used in the construction of
an
airplane? [1]
[6]
You may use the following table to aid you in answering Question
7.
Hint : Zinc ions react with aqueous ammonia to give a white
precipitate that issoluble in excess ammonia giving a colourless
solution.
Solution of copper(II) chloride
7. to
