Practice questions
Particle model and separation techniques
April 2015
24 minutes
38 marks
Page 1 of 18
Q1.
Zoë wants to investigate the way rock is worn away by running water.
She uses a long piece of ice rather than a piece of rock.
She places the ice in a sink and lets a thin stream of cold water run slowly over it.
(a)
The thin stream of water starts to change the shape of the piece of ice.
What shape would form in the top of the piece of ice?
......................................................................................................................
1 mark
(b)
Zoë’s experiment was not a good way of showing how rocks are worn away by water. The
ice was worn down a little, but mostly it got smaller for a different reason.
Why did the piece of ice get smaller?
......................................................................................................................
1 mark
Zoë measures the height of the piece of ice at different times. She plots a bar chart of her
results.
Page 2 of 18
(c)
Draw in the bar for the height of the ice after 3 minutes.
1 mark
Maximum 3 marks
##
Some crushed ice at –20° C was placed in a beaker. A thermometer was put into the ice,
and the beaker was heated gently for 15 minutes.
The graph shows how the reading on the thermometer changed over the 15 minutes.
(a)
By how much did the temperature in the beaker change during the 15 minutes?
.............................................. °C
1 mark
(b)
Which letter on the graph shows:
(i)
when the ice is melting? .........................................
1 mark
(ii)
when the water is boiling?........................................
1 mark
Page 3 of 18
(c)
During the experiment, the beaker and its contents were quickly removed from the
heat and weighed on a balance at the following times.
at 0 minutes
at 5 minutes
at 10 minutes
at 15 minutes
(i)
At which two times would you expect the readings on the balance to be
the same?
....................... minutes and .................... minutes
1 mark
(ii)
Between which two of these times was the mass of the contents of the beaker
changing most rapidly?
....................... minutes and .................... minutes
1 mark
Maximum 5 marks
Q3.
(a) Methane can be a gas, a liquid or a solid. In the diagram below, arrows P, Q, R and S
represent changes of state.
The boxes on the right show the arrangement of particles of methane in the three different
physical states.
Each circle represents a particle of methane.
Page 4 of 18
(i)
Draw a line from each physical state of methane to the arrangement of particles in
that physical state.
Draw only three lines.
1 mark
(ii)
Arrows P, Q, R and S represent changes of state.
Which arrow represents:
evaporation? ............................................................
melting? ...................................................................
2 marks
(b)
Methane is the main compound in natural gas. The scale below shows the
melting point and the boiling point of methane.
Methane has three physical states: solid, liquid and gas.
(i)
What is the physical state of methane at –170°C?
.............................................................
1 mark
(ii)
The formula of methane is CH4. The symbols for the two elements in methane are C
and H.
Give the names of these two elements.
element C .............................................
element H ............................................
2 marks
(iii)
When methane burns, it reacts with oxygen.
One of the products is water, H2O.
Give the name of the other product.
..............................................................
1 mark
Maximum 7 marks
Page 5 of 18
Q4.
Some roads are made of concrete. The concrete is laid in sections with small gaps
between them.
not to scale
(a)
(i)
What happens to the size of most objects when they get hotter?
............................................................................................................
............................................................................................................
1 mark
(ii)
When the temperature rises, what will happen to the gaps between the
concrete sections?
............................................................................................................
............................................................................................................
1 mark
(iii)
When the temperature rises, what might happen to the sections of concrete if there
are no gaps between them?
............................................................................................................
............................................................................................................
1 mark
(b)
The gaps between the concrete sections are filled with tar. The tar becomes soft when it is
warm.
Why is it important that the tar becomes soft?
......................................................................................................................
......................................................................................................................
1 mark
Maximum 4 marks
Page 6 of 18
Q5.
Cathy has two orange drinks, X and Y. She uses chromatography to identify the coloured
substances in the drinks. Her experiment is shown below.
Cathy made the chromatogram below using drink X, three food colourings, E102, E160,
E110, and drink Y.
(a)
(i)
Use Cathy’s chromatogram to identify the two coloured substances in drink X.
Write their E numbers below.
1. …………………..…………………………
2. …………………………………….……….
2 marks
Page 7 of 18
(ii)
Draw another spot on Cathy’s chromatogram to show what it would look like if drink Y
contained E102 as well.
1 mark
(iii)
Chromatography separates the coloured substances in a drink.
How can you tell from a chromatogram how many coloured substances
there are in a drink?
..……………………………………………………………………………….
..……………………………………………………………………………….
1 mark
(b)
(i)
The spots show up well on filter paper. Give one other reason why filter
paper is used in this experiment.
..……………………………………………………………………………….
..……………………………………………………………………………….
1 mark
(ii)
The line across the bottom of a chromatogram should be drawn with a
pencil, not with ink.
Why should the line not be drawn with ink?
..……………………………………………………………………………….
..……………………………………………………………………………….
1 mark
Maximum 6 marks
Q6.
Rema used the apparatus below to distil 100 cm3 of water-soluble ink.
apparatus A
not to scale
Page 8 of 18
(a)
Which processes occur during distillation?
Tick the correct box.
condensation then evaporation
evaporation then condensation
melting then boiling
melting then evaporation
1 mark
(b)
Give the name of the colourless liquid that collects in the test-tube.
.....................................................
1 mark
(c)
What would the temperature reading be on the thermometer when the
ink has been boiling for two minutes?
..............°C
1 mark
(d)
(i)
Water at 15°C enters the condenser at X.
Predict the temperature of the water when it leaves the condenser at Y.
..............°C
Explain this change of temperature.
.............................................................................................................
.............................................................................................................
1 mark
(ii)
Give two ways in which the water vapour changes as it passes down the
glass tube in the condenser.
1. .........................................................................................................
1 mark
2. .........................................................................................................
1 mark
Page 9 of 18
(e)
Peter used the apparatus below to distil 100 cm3 of water-soluble ink.
apparatus B
not to scale
Why is the condenser in apparatus A better than the glass tube and beaker of
water in apparatus B?
......................................................................................................................
......................................................................................................................
1 mark
maximum 7 marks
Q7.
(a) Amy’s family are at the beach during the summer.
Amy and her sister have a bucket containing seawater and sand.
Page 10 of 18
Read the following statements.
Which are true and which are false?
Tick one box for each statement.
true
false
Water is a solvent for salt.
Sand sinks in water because water is more dense than sand.
When a solid dissolves in water, the solid is called a solute.
2 marks
(b)
Seawater contains dissolved salt.
Describe what Amy can do to separate and collect pure water from seawater.
........................................................................................................................
........................................................................................................................
2 marks
(c)
Draw a line from each of the substances below to the group that it belongs to.
Draw only three lines.
Draw a line from each group to the correct description.
Draw only three lines.
2 marks
maximum 6 marks
Page 11 of 18
M1.
(a)
any one from
•
a dip
•
a hollow
accept ‘a hole’
•
a dent
accept a drawing of a hollow
do not accept ‘it gets thinner’
1
(b)
it melted
accept ‘because the air or water was warm’
1
(c)
a bar at 3 minutes showing a height of between 10 and 8 cm
1
[3]
##
(a)
121
do not accept ‘120’
1 (L5)
(b)
(i)
Q
1 (L5)
(ii)
S
1 (L5)
(c)
(i)
0 and 5
both stages are required for the mark
1 (L5)
(ii)
10 and 15
both stages are required for the mark
1 (L5)
[5]
Page 12 of 18
M3.
(a)
(i)
all three lines must be correct for the mark
1 (L6)
(ii)
evaporation: P
1 (L5)
melting: R
1 (L5)
(b)
(i)
liquid
1 (L6)
(ii)
carbon
1 (L6)
hydrogen
1 (L6)
(iii)
carbon dioxide
accept ‘CO2’
accept ‘carbon monoxide’ or ‘CO’
accept ‘carbon’ or ‘soot’
answers must be in the correct order
1 (L6)
[7]
Page 13 of 18
M4.
(a)
(i)
they increase
accept ‘they expand’ or ‘they get bigger’
1
(ii)
they will decrease
accept ‘they will get smaller’
or ‘they will shrink’ or ‘they get filled up’
do not accept ‘they get closer together’
1
(iii)
they might bend or crack or break up
1
(b)
it can flow when the gaps get smaller or so that the gaps can shrink
accept ‘ it can get squeezed out’
or ‘it can be squashed’ or ‘it can flow’
accept ‘it lets the concrete expand’
or ‘so that the road does not get damaged’
1
[4]
M5.
(a)
(i)
E102 and E160
answers may be in either order
accept ‘102 and 160’
2 (L5)
(ii)
another spot drawn above the spot of drink Y and at
the same height as E102
the whole of the spot for drink Y should be
drawn within the dotted lines
1 (L5)
(iii)
count the number of spots above the spot of drink
accept ‘from the number of dots’
accept ‘count them’
1 (L5)
Page 14 of 18
(b)
(i)
filter paper absorbs water
accept ‘it soaks up water or solvent’
accept ‘it is absorbent’ or ‘the water goes up it’
do not accept ‘it does not break up when wet’
1 (L5)
(ii)
any one from
•
it might dissolve or smudge
accept ‘it forms its own chromatogram’ or ‘it runs’
accept ‘pencil does not dissolve or smudge
or form its own chromatogram’
1 (L5)
[6]
M6.
(a)
evaporation then condensation
if more than one box is ticked, award no mark
1 (L5)
(b)
water
accept ‘distillate’
1 (L5)
(c)
100
accept a temperature from 99 to 101
1 (L5)
(d)
(i)
a temperature above 15 but below 100
any one from
•
it is heated by the water vapour
accept ‘vapour or steam or hot water’ for water vapour
•
thermal energy or heat is transferred from the water vapour
accept ‘it heats up’
both the answer and the correct explanation are required
for the mark
1 (L6)
(ii)
any one from
•
it condenses
accept ‘it makes condensation’
•
it changes to a liquid
accept ‘it is liquid’
accept ‘it changes state’
accept ‘it turns to water’
1 (L6)
•
its temperature falls
accept ‘it cools’ ‘it changes temperature’ is insufficient
1 (L6)
Page 15 of 18
(e)
any one from
•
cold water replaces warm water
accept ‘it cools the water vapour better or more efficiently
or quickly’
accept ‘it will work faster’
•
the water stays cold or cooler
•
there is a bigger difference in temperature between the water
vapour and the water
•
some vapour escapes in B
accept ‘it is cooled over a bigger length or for longer’
accept ‘more water is collected’
1 (L6)
[7]
M7.
(a)
•
true
false
for all three correct boxes ticked, award two marks
for any two correct, award one mark
2 (L6)
(b)
•
evaporate the water or evaporation
accept ‘heat it’
accept ‘it goes from liquid to gas’
accept ‘boiling’
do not accept an incorrect use of evaporation,
e.g. ‘she evaporates salt from sand’
1 (L5)
•
condense the water vapour or condensation
accept ‘it goes from gas to liquid’
do not accept ‘it condenses to water vapour’
1 (L5)
accept, for two marks, ‘distil or distillation’
accept, for one mark, ‘condensation then evaporation’
Page 16 of 18
(c)
all three lines are required for one mark
if more than one line goes from any one box,
do not award the mark
1 (L5)
all three lines are required for one mark
if more than one line goes from any one box,
do not award the mark
1 (L6)
[6]
Page 17 of 18
Page 18 of 18