Chemistry Reference
In-Depth Information
c
Sulfuric acid is a strong acid, ethanoic acid is a
weak acid.
Explain the difference between a strong acid
and a weak acid. [2]
[Total: 10]
(Cambridge IGCSE Chemistry 0620 Paper 31
Q4 June 2008)
(iii)
Draw a diagram to show the arrangement
of the electrons in a molecule of methane,
CH
4
.
Use
• for an electron from a carbon atom
x
for an electron from a hydrogen atom. [1]
(iii)
Methane belongs to the alkane
homologous series.
Name
one
other alkane. [1]
[Total: 13]
(Cambridge IGCSE Chemistry 0620 Paper 22
Q7 June 2010)
24
Three forms of carbon are diamond, graphite and
Buckminsterfullerene.
carbon
atom
Inorganic
25
Water is an important raw material in industry.
a
State
one
use of water in industry.
[1]
b
Describe a chemical test for water.
test ______
result ______
diamond
graphite
Buckminsterfullerene
[2]
a (i)
State
one
difference in structure between
Buckminsterfullerene and diamond. [1]
(iii)
State
two
differences in structure between
graphite and diamond. [2]
b
State the type of bonding between the carbon
atoms in diamond.
c
A small piece of potassium was placed in a
beaker of water.
The equation for the reaction is
2K(
s
) + 2H
2
O(
l
) → 2KOH(
aq
) + H
2
(
g
)
(iii)
Describe a test for the gas given off in this
reaction.
test ______
result ______
[2]
(iii)
What is the most likely pH of the solution
in the beaker when the reaction is complete?
Put a ring around the correct answer.
pH 2
pH 6
pH 7
pH 8
pH 12
[1]
d
Water is formed when propane burns.
(iii)
Complete the equation for this reaction:
C
3
H
8
+ 5O
2
→ ______ CO
2
+ ______ H
2
O [2]
(iii)
Which of the following best describes this
reaction?
Put a ring around the correct answer.
carbonisation
combustion
dehydration
hydrogenation
[1]
(iii)
When 4.4 g of propane are burnt in
excess oxygen, 7.2 g of water are formed.
Calculate the mass of water formed when
22 g of propane are burnt. [1]
[Total: 10]
(Cambridge IGCSE Chemistry 0620 Paper 22
Q3 June 2010)
[1]
c
Suggest why graphite is used as a lubricant.
Refer to the layers in your answer.
[1]
d
State
one
use for diamond.
[1]
e
Coal is a fuel containing carbon. When
coal is burnt, carbon dioxide is produced.
Explain how the increase in carbon dioxide
concentration in the atmosphere affects the
world's climate.
[2]
f
Coal also contains small amounts of sulfur.
Explain how burning coal leads to acid rain. [2]
g
Methane is a fuel.
(iii)
Which one of the following is a natural
source of methane?
Tick
one
box.
waste gases from respiration in plants
waste gases from digestion in animals
gases from photosynthesis in plants
gases from forest fires
[1]
