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CARIBI}EAN
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EXAM{NATTONS
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CARIBBEA.N SET'O\DARY EDUCATION CERTIFICATE
EXAMINATION
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CHDMISTTTY
Pitper 02 - General tsr'oficienc1.
) hours
30 trtirtttte-t
READ THE FOLLO\YII'iG Ii{ STRUCTIONS CAREF'ULLY.
1.
This paper consists of Slx questious in TWo sections. Answer ALL questions.
2.
\\-rite r our answers in the spaces provided in this booklel
3.
Do NOT write in the mirgins.
4.
Where appropriate.
5.
You mat
6.
If you
r-rse
ALL WORI(INC MUST BE SHOWN in this booklet.
a :ilenr- nLrn-progr*nrrlabie calculator to ans\\'er questions.
need to rerrrite anY ars!\€r and thrr* i> ilrrt inlrugh space to do so on the
original page, youmustuse the extra lined pagetsl prtxi,Jed at the back of this
booklet. Remember to draw a line through vour original ansner.
If you
use the ertra ltege(s) you MUST rvrite the qrrestion number.clear-lr.irr
the box provided rlt the tolr of theextr"a page(s):rnd. n'here reler.ant, inclucle
the question parr besicle the answer-.
DO I.IOT TT
R\ THI\
P.{GE U]\TILYOUARE TOLD TO DO SO.
C:.: - . l[t1 7 Caribbean Exaurinations Council
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SIlCTION.\
.
AnswerALL questions in this section.
DO NOT spend more than 30 minutes on Question
l_/
1-
Sally performed an experiment u,'hich consisted of a :eries of slt tests to investi-eate the effect of
tempeiature on the rate of reaction. The same rrass of c=i.-ium carbouate, CaCO-, chips rvas allowed
gas was
to react with an excess of dilute hydrochloric acid at difrtrerrt temperatures. Carbon dioxide
produced from the reaction and the time taken to uolle;: i,' ;u:- ..ithis sas for EACH test is showil in
Figure 1.
1.
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TEST
1
50
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TIIST
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25
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20
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10
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lVlateria ls:
'fhe six
tests were carried oLtt at ..i :rerelrt ternperatures usiug the fbllorving reagents:
a\
1.0 g CaCO" chips
100 curr ol'i.0 rnol clrn r
(a)
lrvclr..;.'l-::;
acicl
De0ne 'rate of reacti,-,;
(1 mark)
(b)
(i)
Write a balanced ,,-hemical equation li-.r tire leaction betneen calciunr carbonate and
liydrochloric aci'i.
(2 marks)
ill)
Calculate the volume of carbon dioxide that would bq produced at RTP fiom
1.0 g ol'CaCO, chips.
[RMM: CaCO. : 100:
1 mole
of a gas occupies 24 000 crn3 at RTp.]
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From the sroplr.alfu displayed in Figure I on pge.l, record the times taken
time
takerr
I
.
The
Table
in
carbon dioxide gas to te cillected in the appropriate spaces
)
for Test t has alread-v been recorded.
(i)
TABLEl:RI,SULISAI\IDRI,CIPROCALTIMESFORTESTl-{
Test
Tcmlqr-lIltrc ("C)
Tirnc faken (l)
I1t-e ip r',,u rrl
Tilrtc'
(
s'1)
1
J
4
Lr
(3 mrrrks)
f al;irlate the lecrpr,..;.r i.ll'.c> i i tiir^.
ll-l
:
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:.-:ll to -i decilttal places ir: tlte
.::.'..i..]l:..::slla;es.l..l...rle;'.l.tlL--.l.,.
(iii
t
("l mrrrhs)
graph of retiprocal time versus
using the axes provided in Figure 2 on page ?. pl,rt a
(5 marks)
the poittts.
ttrough
curve
temfrrature foitess 1- 6. Diaw the best
,,
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-7
-
.)
Fernperature ('C)
F
:- . -
Reciprocal time\-ers(ls telttpet'iriurr
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(d)
(i)
Rc::',"':':lr::.''.:r\:lrn(c)(iii)onPilge-'"'e'i'r"''ilc:';:;Ltit;iiit-t''-tpet'at[lrellas
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t1 mark)
(
ii)
StateTWoreasonstrataccountfortheobservecleffect,givenirr(d)(i}.oftemperature
on the rate ofreacdon'
oC'
(e)UsetlregraphdrawnonpageTtodeterrrrinethevalueofthereciprocaltimethatu.ouldhave
carried out at'10
been obtain"a
iitf''"
experiment rvas
12
(0
mtrhs)
test for carbon dioxide'
Describe a confirmatol-Y
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ffi i:IrT iitT' m f i#? ;t"};H
(i)
conn gurario n 2.8 .7 h as
rwo
main i sotopes,,
am
e
ry
Define ,isotopes'.
.ts!
Rd.
A\"
(2 marks)
(ii)
chlolirre-j7 are isotcpes.
(2 rnarlis)
(b)
Sonte elellents hare i-:otopes
that are unstable antl radioacti've.
These are lit.torvn
raclioisotopes" Stale L 1.r, ( ) irses
o1. ra,lioisotopes.
as
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i2 marlts)
(d)
SLrlturisatleli :." ": :
with a choking smell'
='i)ellor'viri'
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1-r!itrairtogire an rci'1ic
gas
(i)Writeabalancedchenricalequatiotl..'rii:i:i:='llnbols.fortlreburningofstriflu.in
air.
(2
(
ii)
Statei-'-'.-..t= l:
marls)
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(itrr\',1.--'::i:'-'lsoKygcll':"''l>-'lll'iel'"'"titlilarl'e'is1i':-\\rltea
.'rith
t'': -"t' Ii't.the l'eactioll t'iil'r ::' ;''tl11i
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(? marlis)
Tot..rl 15 mlrrlis
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with
compound X has the general fornrula C,,Fl''-'
Cornpounds X anclY are sinlple il.',-lrocat'bons.
C,,l{.,, with u : 3 '
n : 4' anci Con]pounci Y has the s"r-,era1 lormula
(a)
compound belongs'
State the homologous sei'ie' to rvhich EACH
ComPoundX
"""""
CotnponnclY
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'
"""'1"""""'
(2 marhs)
ibisiateotletlseEACHt'iC;'inporttrdXanciCtrllll'rlltl1lti\-'
(2 marl<s)
(c)
strLtctttt'e
Drarv the FULLY DISPL\\'ED ft'rmulae to shorv 1he
ol
C-'olnpoLtud
X
and
Cornpotrncl\-
Structure of CoinPound X
\iructure of CnmpOttnd Y
1;1marks)
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water to form an alcohol'
Compound Y reacts rvith
(d)
formed from Compound Y
Dran the structure oithe alcohol
(i)
Statethereagentsan,JreactionconditionsfortheconversionofCompt-rundYto
(ii)
the alcohol.
Reagents
Ru'.r;il.l'l', Crri i'''
(2 rnarhs')
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-13SECTION B
.AnswerALL questions in this section.
The circuit in Figure 3 can be used to test
if
a substance conducts electricity.
Pow'cr supply
Bulb
EmpE- corteiner
Electrode 2
Electrode
1
f igure 3. I)iagrarn of a circuit
(.a
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(2 marl<s)
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thc
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(2 rnarks)
1
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acid
mol dm-: hrdrochloric
L-l-s!'
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- 15 (c)
A sarlple of tnoltetr lea; ::.-nride, PbBr,. is eiectrolysed for three utiuLrtes r,vith a cunent of
6 arnperes. Calcttlate tl:e ::,.:.' of leacl that is deposited at the cathode, given that tr,vo rnoles of
electrotrs are reqttiied 1,:' . :.tate one mole of leacl as shorvn in the following equation:
Pb' (D'r 2e---* Pb(/)
[Q = It: fL{]\tr
pb:207; F:96
500
c rnol-il
a
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(at
is obtained by a process-known as
Ethanol. the main ingredient in maiy alcoholic drinhs,
your descriptiotr' identiff the raw
In
fermentation. Describe the process of fermentation.
materials and prodrrts. and write a relevant chemical equation.
(5 marhs)
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F.,:
BaSedOIttlte
slr'-t
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i- -:.ta,,,\riJbar\i.
:,-..,. ti,ritileSOaplhat
(.1marks)
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t(c)
There are ser e: a.
poll saccltaride. ,i:
(i)
Basecl
- : : - r.'ur35 of polyurers, fol
-' : -.
rrl :
'
the 11,prg. [-]ACLI i-.
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exartrple. pol)'allieltes. llrrl\ esters.
.: Jiaglams sholving the partial struciur'. ,:i'a itoir nrer. decluce
j..Lr\\n. and the rype of polynterization le;1.i,ii,ii thai i',:i,k place irr
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Partial structure of Polymer BB
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partial structure ol
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p,,,lr mer CC
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Toral 15 rriarks
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6.
-20
(a)
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Many irnporlant biologicar processes in plauts and anitriais depenrl on the specific roles of
certain metal ions.
(i)
crop oftomatoes and repofted that the r ield u'as i-ar belolv what
\\,as exprl-teri. -{rmlrsis oithe soil revealedtirattl-iere u'as a deficietrcr of inagtresiutn.
Discusi the imp.r.rrance of magnesiun in plant health. and erpiail: iio* a magnesium
Farmer Jones reaprl
a
deficienc'i can resrh in the lolv yield of tornatoes'
_
t5 marli-sl
dc-ficis':i-'
{2 marks)
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(b)
Many years ago, car exhaust fumes lr€re known
to contain compounds of metals and nonInetals' which could negatiYeb'impact both humans
una trr"
Identify oNE metal
and oNE nonmetal whose compounds *'ere present
""ri."nment.
in car exhaust
fumes. Discuss the effect
of these compounds on human heakh and the environment.
(5 marks)
(c)
Define ogreen chemistry'and discttss the measures that
lrave been taken tc prodlce o .grge*er.
automotive fuel.
(3 marks)
E\D UF TEiT
Total 15 rnarks
IF'YOU IINISH BEFORE TIME IS CAIIED. CUBCX(YOUR
WORI( ON THIS TEST.
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