Chemistry Reference
In-Depth Information
46
Petroleum is separated into useful fractions by
distillation.
(iii)
Ethanol is also formed when yeast
grows in sugar solution. What is this
process called?
Put a ring around the correct answer.
addition
combustion
fermentation
neutralisation
[1]
(iv)
Phosphoric acid is a typical acid. State what
you would observe when a solution of
phosphoric acid is added to
blue litmus,
a solution of sodium carbonate. [2]
[Total: 13]
(Cambridge IGCSE Chemistry 0620 Paper 02
Q6 June 2008)
fractions
fuel gas
petrol
paraffin
diesel
lubricating fraction
petroleum
47
There are two types of polymerisation - addition
and condensation.
a
Explain the difference between them.
[2]
bitumen
b
Poly(dichloroethene) is used to package
food. Draw its structure. The structural
formula of dichloroethene is shown
below.
a (i)
What do you understand by the term
fraction
?
[1]
[2]
(iii)
Which fraction has the lowest boiling
point?
H
[1]
C
l
(iii)
Describe how distillation is used to
separate these fractions.
CC
[2]
H
c
The polymer known as PVA is used in paints
and adhesives. Its structural formula is shown
below.
C
l
(iv)
State a use for
the paraffin fraction,
the bitumen fraction.
[2]
b
Ethene can be made by cracking certain
hydrocarbon fractions.
(iii)
Explain what is meant by the term
cracking
. [1]
(iii)
Complete the equation for the cracking of
tetradecane, C
14
H
30
.
C
14
H
30
→ ______ + C
2
H
4
CH
2
CH
CH
2
CH
OOCCH
3
OOCCH
3
Deduce the structural formula of its
monomer.
[1]
[1]
d
A condensation polymer can be made from
the following monomers.
c
Ethanol is formed when steam reacts with
ethene at high pressure and temperature. A
catalyst of phosphoric acid is used.
ethene + steam
HOOC(CH
2
)
4
COOH and H
2
N(CH
2
)
6
NH
2
Draw the structural formula of this polymer. [3]
[Total: 8]
(Cambridge IGCSE Chemistry 0620 Paper 31
Q8 June 2011)
ethanol
(iii)
What is the function of the catalyst?
L
[1]
(iii)
What is the meaning of the symbol
L
? [1]
