Year 9 iGCSE Fundamentals of Chemistry Test
1.
Name
Four separate food dyes (C, D, E and F) and a mixture of food dyes (X) were
investigated using paper chromatography. The diagram shows the apparatus used.
(a) Why should the water level be below the food dyes?
……………………………………………………………………………………………………………
……………………………………………………….….. ……………………………………………………
1 mark
1
(b) During the experiment the water rises up the paper. The experiment is stopped just before the
water reaches the top of the paper.
The diagram shows the paper after it has been removed from the beaker and dried.
(i) Which of the food dyes C, D, E and F does X contain?
………………………………………………………………………………………………………
1 mark
(ii) Suggest why food dye F did not move up the paper during the experiment.
..................................................................................................................................................
1 mark
(c) Each food dye has an Rf value that can be calculated using this expression:
Rf = distance moved by food dye from base line
distance moved by solvent from base line
Record the distances for food dye D in the table below and calculate its Rf value.
3 marks
Distance moved by food dye D from base line in mm
Distance moved by solvent from base line in mm
Rf value
(Total 6 marks)
2
2.
The diagrams represent the way 'atoms' are arranged in six chemical substances.
Each 'atom' is represented by a circle.
The 'atoms' are labelled with their chemical symbols.
C
C
C
O
C
C
C
O
O
O
3
2
C
H
C
H
H
C
H
C
4
C
C
C
C
Na
Cl
1
Na
Cl
Na
Na
Cl
Na
Cl
Na
Cl
Na
Cl
Na
Cl
Na
S
Na
Cl
Na
Cl
S
Cl
Cl
Na
Cl
Na
Cl
Cl
S
S
Na
S
S
Na
Cl
S
Na
Na
Cl
Cl
Na
Cl
S
6
5
(a)
(i)
Which diagrams represent the structures of chemical elements?
Write the numbers.
.............................................................................................................
1 mark
(ii)
Explain how you made your decision.
.............................................................................................................
.............................................................................................................
1 mark
(b)
Give the formulae of two of the compounds represented in the diagrams.
1. .................................................................................................................
2. .................................................................................................................
2 marks
3
(c)
Give the name of substance 6.
......................................................................................................................
1 mark
(d)
Give the names of the chemical elements whose atoms can be represented by the
following symbols.
C ….………..……….……..…………………………………………………..…
Cl ….………..……….……..…………………………………………………..…
Cu ..………..……….……..…………………………………………………..…..
3 marks
( Total 8 marks )
3.
An experiment was set up as shown in the drawing. After several minutes white smoke of
ammonium chloride, NH4Cl, appeared as shown.
glass tube
of length 100 cm
cork
cork
cotton wool
soaked in
ammonia
solution
(a)
white smoke
cotton wool
soaked in
concentrated
hydrochloric acid
solution
gas given off
relative
molecular mass
ammonia
ammonia
17
hydrochloric acid
hydrogen chloride
36.5
Write a balanced equation for the reaction which produced the white smoke.
......................................................................................................................
b)
(i)
1 mark
Explain why the smoke formed after several minutes, rather than immediately.
.............................................................................................................
.............................................................................................................
(ii)
Explain why the smoke formed nearer to the hydrochloric acid end of the tube
than to the ammonia end.
.............................................................................................................
.............................................................................................................
.............................................................................................................
............................................................................................................
2 marks
(Total 4 marks)
4
4.
The diagram shows the structure of a lithium atom.
KEY
+ = proton
= electron
+
+
+
(a)
(i)
What is represented by
.................................................................................
(ii)
+
+
What is represented by + ...........................................................................
2 marks
(b)
What is the symbol for lithium? ................................................................................
1 mark
(Total 3 marks)
5.
In an experiment a student left some solid sodium chloride in a beaker of water for several
days. The diagrams show the beaker at the start and end of the experiment.
(a) Write the formulae, with state symbols, of the two substances in the beaker at the start
of the experiment.
……………………………………………………………………………………………………………….
2 marks
5
(b)
Name the process by which the chloride ions moved through the water to near
the top of the water.
......................................................................................................................................
1 mark
(c)
Sea water contains dissolved sodium chloride. The following pieces of laboratory apparatus can
be used to make drinking water from sea water.
(i) Draw a labelled diagram to show how these pieces of apparatus can be assembled to do this.
3 marks
(ii) Name the technique used in this process.
......................................................................................................................................
1 mark
(Total 7 marks)
6
6.
(a) Substances can be classified as elements, compounds or mixtures.
Each of the diagrams below represents either an element, a compound or a mixture.
State which one of these is represented by each diagram.
(i)
……………………..
1 mark
(ii)
……………………..
1 mark
(iii)
……………………..
1 mark
(iv)
……………………..
1 mark
(b) Substances can also be classified as solids, liquids or gases.
Each of the diagrams below represents either a solid, a liquid or a gas.
State which one of these is represented by each diagram.
(i)
……………………..
1 mark
(ii)
……………………..
1 mark
(Total 6 marks)
END OF TEST - TOTAL MARKS 34
7