BOTSWANA EXAMINATIONS COUNCIL

Botswana General Certificate of Secondary Education

CANDIDATE
NAME 1&)\\:ElLD NE 1..-SON
CENTRE
NUMBER ~v C( ~5 I0 CANDIDATE
NUMBER rJ JJI
1

l
0569/04
SCIENCE : DOUBLE AWARD
October/November 201 7
Paper4
1 hour 30 minutes

Candidates answer on the Question Paper

Additional Matenals 300 mm ruler

• READ THESE INSTRUCTIONS FIRST

Wnte your candidate name Centre number and candidate number in the spaces provided at the top of this
page
Write 1n dark blue or black pen
You may use a soft pencil for any diagrams, graphs or rough working .
Do not use staples paper clips, highlighters, glue or correction fluid .
DO NOT WRITE IN ANY BARCODES

Answer all questions

Write your answers in the spaces provided on the Question Paper
The number of marks is given in brackets [ ] at the end of each question or part question.
You may lose marks 1f you do not show your working or if you do not use appropriate units.
You may use a calculator

A copy of the Periodic Table 1s printed on page 16.

For Examiner's Use

-----

•
1

3
f--- - '-- -
4

6
1--

Total
J

This document consists of 16 printed pages .

[Turn over

ti BEC 2017
 2
1 /£
(a) A student has at · I
a prot t ransparent parallel-sided perspex block, a soft board, plain paper, a ru er,
rac or and some optical pins.

Describe an experim t th . .
perspex bl k . en e ~tudent can carry out to determine the refractive index of the
oc , using the available materials.

············· ····· ······· ·· ····· ··· ···· ·· ····· ···· ··· ······· ···· ····· ·· ········ ······· ···· ·· ········ ·· ········ ·· ······· ········ ··· ··· ·· ·

··· ········· ···· ······· ·· ····· ····· ··· ······ ·· ········· ···· ······ ······ ·············· ·········· ······ ·· ····· ······· ····· ··· ········· ·· ···· ·· ·· ···

······· ······· ······ ····· ··· ······ ······ ·· ·· ····· ···· ············· ··········•··· ··· ·· ·· ···· ·· ··· ········ ··•·············· ····· .. ······ ·· ········

···· ················· ·· ········· ······ ·• ····· ······················· ·· ··· ······ ········ ···· ·· ·· .. ·· ··· ···· ····· ···············"· ·········· .....

····· ···· ··· ··· ·· ·· ····· ·· ·· ··········· ··········· ······ ··· ·· ············ ······· ····· ··· ··· ·· ·········· ·· ············ ····· ···· ·· ····· ·· ···· ···· ·

······ ···· ··· ········ ······· ··········· ···· ······ ···· ·· ············· ············ ···· ····· ···· ··· ···· ···· ·· ·· ····· ·· ········ ·· •"'·········· ···· ··

········ ······ ·········· ··· ············· ···· ········ ···· ········ ····· ··········· ············ ···· ····· ····· ·· ·· ········ ·········· ··· ··· ········ ···

················· ··· ···· ·················· ···· ···· ···· ·· ···• ······ ··· ·· ··· ··· ·· ·········· ······················· ·· ··· ·· ····· ········ ····· ···· ·· ··

......... .. ................. .. ... ....................................... ............................ ..... .... .... ... .................... ..... (4) 4
(b) Fig. 1.1 shows a set-up used by a student to determine the refractive index n of water.
The student measured the real depth hd and apparent depth ha of a rule .

- - rule

ha ,,

Fig.1.1

(i) Measure and record the lengths hd and ha.

hd = .... ............. .. ....................... .... .

ha= .......... ... ...... .............. ... .. .... .. ...

[1 l
 3

{ii) Determine the refractive index n of water Use the equation

n=~.
ha

n = ......... ........ .... ... .. .. ..... ... ... ..... (11

(i ii ) Suggest one source of inaccuracy when doing this experiment.

....... ........... ....... ..... . ' ....... ....... .. ... ' ... ... ... ' ... ... .. .. ... .. .... .. ... ... .. ... ...... .. ' ... ..... ... ... ............ .. .

......... ........ ....... ··· ······ ........ .. ... ....... ····· ···· ·.. ········ ····· ··· ·· ....··· ··..... .. .... ..... ...... ....... .......... ..[1 ]

(iv ) The experiment was repeated using the same water with a smaller real depth hd.
The student suggests that the refractive index will be smaller since hd is smaller.

State whether the suggestion of the student is correct or wrong . Explain your answer.

statement. ........... ...... ...... .......... ... ........... ....... ... ... .... ................. .... .. ..... .. ... .... .... ... .... ........ .

explanation ..... ..... .. ... ..... ... .. ... .... ......... .... ....... ... .. .... ... ... ..... ........ ..... ..... ......... .... .... ... .... ..... .

······· ·· ·· ····· ·· ··· ··· ··· ······ ········ ·· ···· ······· ·· ··· ········ ······· ·· ·· ···· ····· ·················· ···· ···· ··· ·········· ···· ········
[1]

m
C BEC 2017 0569/04/O/N/17
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 5
E.
2 An expe,irrient is performe d to find the relationship between the length I of a wire and its
res'.s~ance R The total length of the wire is 100 cm .

Fig. : shows the set-up that is used , with the wire connected between points P and Q.
The connection near Q is a sliding contact which can be moved .

• wire

sliding contact

Fig. 2.1

Fig . 2.2(a) and Fig . 2.2(b) show the readings of an ammeter and a voltmeter when the
sliding contact is placed at 1= 20 cm from P.

Fig. 2.2 (a)

Fig. 2.2 (b)

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 6
F0<
&am;ne,,
(a) Table 2.1 shows some of the results of the experiment. Use

Table 2.1

i ucm
I
I! ... .. .. VIV RI ......
0 0.00 0.0
10 0.45 0.9
20
30 0.44 2.8
40 0.45 3.7
50 0.43 4.4

Complete Table 2.1 by

(i) writing the SI units of I and Rat the headings, [1]

(ii) record ing the ammeter and voltmeter readings for l =20cm as shown in
Fig. 2.2(a) and Fig . 2.2(b}, [1]
(iii) calculating R, of each length of wire. Use the equation

V
R= - . [2]
I

C BEC 20 17 0569/04/O/N/ 17
 7 For
Exammors
(b) Plot a graph of R (y-axis) against I (x-axis). [4] USB

I
I

I I
f I.
-- -+- - ~-
I
i I '
I I

-- .-- .. - -- e - ,.._ -,____ - +--- - ,_ ,__,_.. +---- I

--~ I
I
I

I
'- c--
I
--r-
-4 I I ,.

·f-
I

-+
-- --i-.. I
..
,. t d
;
1 l
4

•
I '
,__
I I
I

I
I

.
It

. t
I
I
, I

I i'
l I

I
I
I Ii

-- l - I • . '
t
•
I

.• \
t
p
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t l
. . I I I I
I I •
I I I
I I
I !I
I I

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l I
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;
t
I I I

1 I 'I I
I I

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I

- ,- - 1 I I, I

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... ,__ I

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Q5f;Cl/04/()/!J/17
 8

(c) VVhat ,s the conclus1on that can be made from this experiment?

.[1J

(d) State one precaution which should be taken when doing this experiment.

... [1 l

(e) The average ammeter reading for the experiment is 0.45A

Use your graph to determine the voltmeter reading when the length of the wire is 45 cm
from P Use the equation

V= IR.

voltmeter reading = ........ ... ......... .. .... ... .... .... .. [2]
•

0569/04/0/N/1 7
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 9

3 Some tests are made on solid P and solution Q

Table 3 1 shows the tests observations and conclusions.

Complete Table 3.1

Table 3.1

te sts observations conclusions

------r-- -------- -
(a) Solution Q 1s divided
into two portions

A blue litmus paper is

dipped into one portion of blue litmus paper turns red
solution Q .............................. ... [1 l

b) A few drops of acidified

barium nitrate solution sulphate ion , SO !- present in

I·
are added to another I

•
solution Q.
portion of solution Q . ··· ·· ·· ···· ·· ·· · ······ ····· ··· [2]

I
(c) Solid P is dissolved in
solution 0 . I production of bubbles
I solid P contains
The gas produced is
tested with lime water. lime water turns milky ... ... .. ... .......... ... .......... [1 l

(d) To a porti on of a mixture

from (c) add

(i)..... . ........ ......... .... . .. .

..... .... .... ...... ............ [1l

... ........... . ....... ...... .. ..[1 l IZn' ' or Ca' ' are suspected.
(ii)...... ... .. . .... ... ........... .

• . .... ........ ...... ........... [1]

.. .. ... ... ..... ... ... ... ... ..... [1 l Ca 2+ present.

(e) Identify solid P and solution Q .

solid P ................... ... .. .... .............................. ......... ....... ..... ... ...... .... ... ... ....... ..... ... ........... ..... ...

solution Q ............... ...... .. .. ............. ... ........... ........ ... ..... ... .... ........... ............... .. ..... .... ... .. ... .... i2i

C BEC 2017 0569Al4/O/N/17 [Turn over

 10 For
Exammer 5
4 Fig 4 1 shows the set- f . . Use
hydrochloric acid b t·t up_0 a~ experiment used to determine the concentration of
Y I ration with sodium hydroxide solution.

_____ burette containing

hydrochloric acid

25.0 cm 3 of 0.100 mol / dm

sodium hydroxide solution
with methyl orange indicator
3
•
Fig. 4.1
3
(a) Name the apparatus used to measure accurately 25.0 cm of sodium hydroxide solution .

.. . . ... . . .. .. .... .. ..... ................... ..................................... .. ... .... ............ ....... .. ..... .. ... .. ......... ......[1]

(b) Fig. 4.2 shows the burette readings before and after each titration .

titration 2
titration 1

•
.J..
before after
before after titration
titration
titration titration

Fig. 4.2

0569/04/O/N/ 17
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 11 For
Exammor s
Complete Table 4 1 by recording the burette readings. u~

Table 4.1

reading after titration /cm~

titration 1 f tr;t,on 2

reading before titration / cm 3 1 t

volume added I cm 3
I
[3]
(c) Calculate the average volume Vavofthe acid used .

Vav =.. .... .. .... ........... .. ... ... .. .. ... .. [1]

• (d) The equation for the reaction is:

NaOH(aq) + HC l(aq) - - + NaC Z(aq) + H20 (1)

Calculate the concentration of hydrochloric acid.

concentration= .............................. .......... mol/dm 3 [1]

(e) A student is given 4.0 g of solid sodium hydroxide.
3
The student is asked to prepare 1.0 dm of 0.100 mol I dm 3 stock solution of sodium

.
hydroxide.

Describe how the student can prepare the solution.

. .. .. .. ........ ..... ... ....... ..... ....... .. .... ..... ........ ...... ... ........ .... .. ........... .... .. .. .. ....... .... .... ..... ....... .. ........ .. .

·· ·· ······ ·• ··· ·· ······· ····· ·· ·· ······ ·· ··· ·• ·········· ··· ··· ·· ··· ················· ················· ···· ··········· ··· ··· ·· ····· ··· ·····" ·· ····

······ •··· ··· ···· ·· ···· ··• ······· ···· ····· ····· ·········· ··· ··· ················· ···· ···· ··· ·· ············ ··· ···· ······· ·· ··· ····· ··· ··· ··· ·······

····· ·· ···· ·· ··· ·· •·· ··· ·•· ·.. ·· .. ··· ··· ····· ········ ·· .. ·•··········· ··· ········ ····· ········ ··· •·.. ,·.. .. ... .. ... ...... .... .. .. , ... ... ... .....
,

···· ·· ······ ··· ······· ··· ··· ····· ·· ··· ··· ··· ···· ······ ·· ·· ········ ········ ··· ·· ···· ·· ····· ···· ·· ············· ······ •··· ········•·· ····· ··········

. ... ... . ... .. ., ........... .. ... ........ ...... .. ... ........ .... .. ....... ... .. .. .. ... .. .. ......... ........ .. .. .... ....... .. .... ... ..... ...... ..

··· ·· ·························· , ., ...... .... ... ........ ... ... ..... .. ..... ..... ... .... ... ..... .... ... .. ........... ......... .. .. .. ..... ... ..... ..

r.\~ .. , . ····· ····· ··· ·· ···· ···· ····· ···· ······ ·· ··· ···· ··•·· ·· ··· · ···• ··· ···· ··· ····· ········ ······ ··· ·· ··· ······· ····· ··• ····· ······ ······ ······ ·
m .. ... ... ...... .. ... ... .. ......... .. .. .. ....... .. ... .... ............................ ... .. ...... .. .... ........... .... .. . .. .. .. ..... .. .. .. (41
 12 For
Exdmmer,
5 Fig. 5 1(a) and Fig. 5.1(b) show photographs of leaves of two plants. Use

Fig. 5.1(a) Fig. 5.1(b)

•
(a) State two visible differences between the leaves in Fig . 5.1(a) and Fig. 5.1(b).

1 ......... ........ .... ... .. ......... .... ... .... ......... ..... ...... ............... ··· ·· .......... .·•· ······ ... ··· ······ ...... ....... ........ .

2 ···· ···· ············ ·"···· ·· ·· ·· ·· ··· ····· ·.. ·· ·· ···· ······· ······ ··•········· ··· ···· ········"· ···· ··· ···· ··" ···•··· ···· ······· ···· ···· ··
[2]

(b) Make a large drawing of the leaf in Fig. 5.1(b).

[3]

0569/04/O/N11 7
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 13 For
&:am.ners
(c) Measure and record Use

• the length of the longest side of the leaf in the photograph in Fig . 5.1(b) .

• the length of the same side of the leaf in your drawing

Draw lines on Fig. 5.1 {b) and on your drawing to indicate where the measurements
were taken .

longest of photograph = ..... .. ....... ... .. •.. ••..···· ········· ·······

longest of drawing = .... ... ...... .. ... .. .. •••••••••····•··············· ·

[2]
(d) Calculate the magnification of your drawing. Use the equation

magnification = longest length of drawing

longest length of photograph

• magnification= ..... .. ...... .... ....... ......... .... .. .... .... ...... ..(11

:,-2,i
Ji
0569/04/O/N/17
"' BEC 20 17 [Turn over
 14
6
A student cuts a potato strip and tests it for starch by adding iodine solution to it Use

(a) state th e result of a positive test for starch.

··············· .. .......... ................................. , ...... ······ ·· .. ..... .. ······ ..... . .. ... ... .. .... .[1 l

(b) ~ tudent investigates the action of amylase solution on starch .

e uses the set-up shown in Fig . 6.1.

/ >----test-tube

- +--- warm water

amylase solution --+----. ,-+-----1-- - potato strip

Fig. 6.1

(i) Suggest a control for the experiment.

.. ... ....... ..... ····· ···· ..... ..... ... .. ,... .... ..... ... .... ....... .. ... ...... ........... ......... .. .... ... .. .. ... ........ ......... .. [1 ]

(ii) Afte r 30 minutes, the student used iodine solution to test the contents of the test-tube
for starch .

Predict and explain the result that she would obtain.

result. ...... ... ... .... .......... ..... ... ..... ....... .... ...... .. .... ... .. .................... .. ...... ..... .. .. ...... ........ ..... ... ..

explanation... ...... .... ... ........... ............. ....... ........ ... .......... ..... .. ... .... ... .... .... ... ...... .. ... ..... ...... .
[1 l

(iii) Explain why the potato strip and amylase solution should be placed in warm water.
·· ···· ···· ··· ·· ·· ... ... ... ..... ..... ..... .. ... ... .. ..... ....... ..... .. ... ...... .. ... ..... .. ... .... .... .. .... .. .... ...................... ..

..... .... ......... ....... ......... ... .. .... ... .................. ... ... ..... ... ........... ..... ...... ...... .... .. .... ... ....... .. .... .. [1] -

(c) The student suggests that a potato strip contains less sugar than a pumpkin strip.

Describe an experi ment which can be carried out to find out whether the suggestion
is correct .

.. .. .... ···· ····· ···· ··· ·· ·•····· ········ ··· ···· ····· ··· ··· ··············· ·· ·· ····· ··•· ···· ······ ···•··•· ···· ·· ···· ·· ··· ·· ·· ··· ···· ··· ····· ···

················ ·· ·•·· ··· ····· ········ ··· ···· ·· .. ···· ······· ·.. ................ .. ........... ....... .. .... ...... ... . .............. ...... .. .
,

········· ·· ················· ·········· ··· ········ ······ ·· ·· ······ ·•··· ······ ···· ··· ............. ..... ... ...... ..... . ... ..
········ .. •····· ··· ·
.......... ,. , .. ... ... ..... ... .. .... .. .... .... .. .......... ....... ... ...... ...... ..
··········· ··· ····••"•'"·······••"··· ··· ··• •" ·· ···•• "
..... ... ...... ... ..... ... .. ... ........... ...... ...... ,.. ,..... .,... ..... .. .. .. ...... .. .[4]
··· ····· ······ ··••" ····
 15 -,J,., n

(d) A student cuts strips from stem tubers of plants E and F

She places the strips in a sugar solution
Frg. 6 ·2 shows the strips before they were placed ,n the sugar solution .

plant E strip
J plant F strip

Fig. 6.2

(i) Measure and record the lengths of the strips.

plant E length of strip = .......... .. .......... ••••••... ··· ·····

plant F length of stri p = .................. .... ... •· ••·····.. ···

[1 l

(ii) Fig. 6.3 shows the strips after they have been left in the sugar solution for 30 minutes.

plant E strip plant F strip

Fig. 6.3

Measure and record the new lengths of the strips.

plant E length of strip = .... ............................. ..... .

plant F length of strip =

[1]

(iii) The student suggests that the cell sap of plant F has more sugar than the cell sap of
plant E, since it has a greater increase in length.

•
Do the results of the experiment support the suggestion? Justify your answer.

results ......... ... .................. .... ..... ............... ... ...... .... ........ ... ...... .... .. ... ... .... ... .... .. ..... ....... .... .

justification ................ .. ................. .... ............ ... . ..... ... ..... .... ....... .. ........... .......... .... .... ... .

······ ········ ··· ···· ····· .. ··················• ···· ·· ................................ ... .. ................... ... .... , ...... ..,, ......... .
[2]

;;;;;;;;i"11510n 10 reproduce ,rems where third par1y owned matenal protected by copynght Is Included has been sought and dea~ where possible Every
reaeonable effort has been made by lhe publisher (SEC) to trace copynght holda~, but ,r any Items requirtng clearance have unw,tt,ngly been included. the
pubhsher wtll oe pleased to make amends at the earliest possible opportun,ly •

10 BEC 2017 0569/04/O/N/17