Chemistry Reference
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(iii)
What happens to the unreacted nitrogen
and hydrogen? [1]
(iv)
State
one
advantage and
one
disadvantage
of using a lower temperature.
31
Choose an element which fits each of the
following descriptions.
(iii)
It is a yellow solid which burns to form
an acidic oxide.
[2]
[Total: 9]
[1]
(iii)
This element is a black solid which,
when heated, forms a purple vapour.
[1]
(iii)
Most of its soluble salts are blue.
[1]
(Cambridge IGCSE Chemistry 0620 Paper 31
Q4 November 2010)
(iv)
It has a basic oxide of the type MO
which is used to treat acidic soils.
[1]
30
Lead is a grey metal.
a
State
two
physical properties which are
characteristic of metals.
(v)
It is an unreactive gas used to fill
balloons. [1]
[Total: 5]
(Cambridge IGCSE Chemistry 0620 Paper 31
Q1 June 2010)
[2]
b
To which Group in the Periodic Table does
lead belong? [1]
c
An isotope of lead has the mass number 208.
Complete the table to show the number of
subatomic particles in an atom of this isotope
of lead. Use the Periodic Table to help you.
32
This question is about some compounds of
nitrogen.
A mixture of ammonium sulfate and sodium
hydroxide was warmed in a test-tube. The gas was
tested with moist red litmus paper.
Type of particle
Number of particles
electrons
protons
neutrons
red litmus paper
[3]
d
When lead is heated in oxygen, lead(
ii
) oxide is
formed. Write a word equation for this reaction. [1]
e
When lead(
ii
) oxide is heated with carbon, lead
and carbon monoxide are formed.
PbO + C → Pb + CO
(iii)
Which substance becomes oxidised during
this reaction? [1]
(iii)
Carbon monoxide is a covalent compound.
Which one of these statements about
carbon monoxide is correct?
Tick
one
box.
ammonium sulfate
and sodium hydroxide
heat gently
a
State the name of the gas released. [1]
b
State the colour change of the litmus paper. [1]
c
Complete the word equation for the reaction of
ammonium carbonate with hydrochloric acid.
ammonium + hydrochloric → ___ + ___ + ___
carbonate
It is a solid with a high melting point.
It conducts electricity when it is
a liquid.
acid
[3]
It is a gas at room temperature.
d
Ammonium salts such as ammonium nitrate,
NH
4
NO
3
, and ammonium chloride, NH
4
Cl,
are used as fertilisers.
(iii)
Explain why farmers need to use
fertilisers. [1]
(iii)
Explain why ammonium nitrate is a better
fertiliser than ammonium chloride.
It forms about 1% of the atmosphere.
[1]
[Total: 9]
(Cambridge IGCSE Chemistry 0620 Paper 22
Q6 June 2010)
[1]
(iii)
Calculate the relative formula mass of
ammonium nitrate.
[1]
