a/l chemistry 2014 model paper (sipsara udana, uva...
TRANSCRIPT
1
A/L Chemistry 2014 Model Paper (Sipsara Udana, Uva Province)
Dr Vajira Seneviratne, University of Peradeniya jHQy.; rpkd
A - fldgi
m%Yak y;rgu ms<s;=re imhkak'
01. (a) hk uQ, øjHh wdYs%;j ms<s;=re imhkak'
1) yd hk TlaislrK wxl olajk uQ, øjHh jkafka"
2) j¾Kj;a Tlaihsv idokqfha"
3) m%n,;u Tlaisydrlh jkafka"
4) m%n,;u Tlaisldrlh jkafka"
5) nyqrEmsl;dj fmkajk uQ, øjH jkafka"
6) Tlaihsvh iy yhsv%hsvh hk folg wdï,sl jkafka"
7) by<u w.hla we;s c, ødjKhla ,nd fokafka"
(b) my; wlajd we;af;a øjHh lSmhl øjdxl úp,kh fõ'
øjHh ialkaOh øjdxlh$˚C
Ne 20 -248
Ar 40 -189
H2O 18 0
NaF 42 993
C 12 3550
i. by< úp,;djhka meyeÈ,s lrkak'
ii. NaF j,g idfmalaIj MgF2 j, øjdxlh jeä fõoehs , wvq fõ±hs meyeÈ,s
lrkak'
(c) A yd B hkq mrudKql l%udxlh 20g wvq uQ,øjH folls' 30˚C § A c,h iuÕ C
kï jdhqj msglrñka D ødjKh idohs' B c,h iuÕ m%;sls%hd fkdlrk kuq;a D
ødjKh iuÕ m%;sls%hd lr C jdhqj msg lrñka E ødjKh ,nd foa'
i. ridhksl ixfla; Ndú;d lr A, B, C kï lrkak' Uva P
rovinc
e Sips
ara U
dana
& st
uden
tlank
a.com
2
ii. E ødjKhg HCl iaj,amh neÕska tla lrk úg ±lsh yels ksÍlaIKh
fudkjdo@
02. (a) ixY=oaO c,h T kue;s ksh; WIaK;ajfhaoS tys jdYamh iu`. .;sl
iu;=,s;;djfha we;' túg jdYam l,dmfha mSvkh P˚ úh' tu WIaK;ajfha§u
c,hg D2O tla lrk ,È' túg moaO;sfha jdYam mSvkh P úh' c,fha ;dmdxlh
100˚C jk w;r D2O j, ;dmdxlh 102˚C fõ' ñY%Kfha 75% c,h wvx.= jk
w;r b;sßh D2O fõ'
i. ñY%Kfha D2O j, ujq, Nd.h i|yd m%ldYkhla jHq;amkak lrkak'
ii. ñY%Kfha uq¨ jdYam mSvkh hk iïu; wdldrhg úp,kh jk
nj fmkajkak'
iii. ñY%Kfha jdYam mSvk ixhq;s m%ia:drh w¢kak'
iv. D2O m%;sY;h 80% la jk ødjKhla Nd.sl wdijkhg Ndckh l< úg
ixrpl fjka jk whqre ;dmdxl ixhq;s m%ia:drfha olajkak'
c,h iuÕ t;fkda,a yd HCl ñY% l< úg c,fha jdYam mSvk by; moaO;sfha
mSvk j,g idfmalaIj olajkak'
v. by; (v) ys m%ldY j,g fya;= moaO;sj, wka;¾ wKql wdl¾IK n, weiqfrka
olajkak'
(b)
i. 1000K WIaK;ajfha§ CO2 j, j¾. uOHhk uQ, m%fõ.h .Kkh lrkak'
ii. CO2 j, Wmßu iïNdjHh m%fõ.h f,i woyia lrkafka l=ulao@
iii. CO2 j, m%fõ. jHdma;sh ksrEmKh lrk fnda,aúiaudka jHdma;sh my;
m%ia:drfha ksrEmKh lrkak'
wKq Nd.h
m%fõ.h
iv. CO2 j, Wmßu iïNjHh m%fõ.h iy j¾. uOHhk uQ, m%fõ.h by;
m%ia:drfha o< jYfhka olajkak'
3
v. WIaK;ajh 2000 K olajd by< kexjQ úg CO2 j, m%fõ. jHma;sh fjkia jk
whqre m%ia:drfha olajkak'
vi. m%ia:drfha ,nd .; yels ks.uk 2 olajkak'
03. (a) my; m%;sls%hd j,ska ,efnk M, j, jHQy ,shkak'
i.
ii. 1 ) CH3MgCl
2 ) jeämqr H2SO4
iii. NaNO2 / HCl(5 - 10o C) D NaOH E
(b) my; ksÍlaIK i`oyd fya;= bÈßm;a lrkak'
i. kue;s ixfhda.h úc,SlrKhg Ndckh l< úg m%Odk
M,h f,i ,efí'
ii. A) B) C)
A, B yd C c,Sh NaOH iuÕ m%;sls%hd lrkq ,nkafka fjkia wdldr j,sks'
Uva
Prov
ince S
ipsara
Uda
na &
stud
entla
nka.c
om
4
(c) my; ldnksl mßj¾;k wju mshjr .Kkdjlska isÿ lrkafka flfiao@
i.
m%;sldrl NaBH4, conc, H2SO4, ldnksl fmfrdlaihsâ" HBr, NaOH, PCl3, Mg,
úh<s B;r" KMnO4
ii. +
m%;sldrl Zn(Hg), HCl, PCl5, LiAlH4, Mg úh<s B;r H2SO4, Br2, CCl4, C2H5OH,
KOH ks¾c,Sh AlCl3
04. (a) c,Sh ødjKhl Fe3+, Al3+ yd Co2+ whk we;' fuu c,h ødjKhg NH4Cl oud bka
miq NH4OH tl;= lr r;a lrk ,È' miqj ødjKh fmrd .kakd ,È' bka miq
fmrKhg H2S nqnq,kh lrk ,È'
i. m<uq wjlafYamfha j¾Kh l=ulao@
ii. wjlafIamfha wvx.= øjH j, iQ;% ,shkak'
iii. fmrKfha j¾Kh ,shkak'
iv. fmrKfha wvx.= ixfhda.fha iQ;% ,shkak' m<uq wjlafYamh c,Sh NaOH j,ska
fidaok ,È' fidaÞ ,efnk ødjKhg HCl ìxÿ jYfhka tl;= lrk ,È'
v. by; kj fmrKhg HCl tla l< úg ,efnk ksÍlaIK fudkjdo@
vi. by; ksÍlaIK j,g wÞ< m%;sls%hd ,shkak'
vii. by; m<uqj ,efnk fmrKhg H2S nqnq,kh lsÍfï§ ,efnk ksÍlaIK
,shkak'
5
(b) my; m%;sls%hd fYa%‚h i,lkak'
(NH4)2 Cr2O7 SO2 / H2SO4 c,Sh ødjKh
NH4OH
>kh
jeämqr c,Sh NaOH oeóu'
H2O2
i. A isg E olajd øjH j, iQ;% ,shkak'
ii. my; wjia:d i|yd iólrK bÈßm;a lrkak'
a. (NH4)2CrO7 D
b.
A
B C
D
E
Uva P
rovinc
e Sips
ara U
dana
& st
uden
tlank
a.com
6
rpkd
B – fldgi (05,06, 07)
m%Yak follg muKla ms<s;=re imhkak'
05. (a)
i. hkq c,fha u| jYfhka ødjH >k whksl ixfhda.hls' fuys i|yd
m%ldYkhla wÞ< uq,O¾u weiqßka jHq;amkak lrkak'
ii. c,Sh ødjKhla ;=, Ag+(aq), Hg+2(aq) iy whk wvx.=h' fïjdfha tlsfklg
idfmalaIj idkaøK 0.1 moldm-3 fõ' fuu ødjKhg NaI ødjKhla l%ufhka
tl;= lrk ,o kï whvhsvhla f,i uq,skau wjlafIam jkqfha l=uk
legdhkhg o fmkajd fokak'
wÞ< WIaK;ajfh§ AgI(s) j,
HgI2(s) j,
iii. fojk legdhkh wjlafIam ùu wdrïN jk fudfydf;a§ wjlafIam jQ
lgdhkfha" wjlafIam fkdù ødjKfha b;sÍ ù we;s legdhk idkaøK m%;sY;h
fldmuK o@
(b) jdhqf.da,Sh jd;fha mßudj wkqj 0.035% la CO2. mj;S' lsishï WIaK;ajhl§
CO2(g) CO2(aq) hk iu;=,s;;dj i|yd fykaß ksh;h KH =
3.3 × 10-4 mol dm-3 K Pa-1 fõ'
1) mSvkfha§" CO2 j, c,fha ødjH;dj .Kkh lrkak'
2) c,fha Èhù we;s CO2 c,h iuÕ m%;sls%hd ù ldnfkag yd nhsldnfkag whk idohs'
i. HCO3-(aq) CO32-(aq) + H+(aq) hk iu;=,s;;djg i|yd
m%ldYkhla ,shkak'
ii. ldur WIaK;ajfha§ fuu iu;=,s;h i|yd iu;=,s;;d ksh;fha w.h
c,h idïm,hl wvx.= HCO3- whk idkaøKh CO32-
whk idkaøKh fuka oi .=Khla fõ' fuys fidhkak'
iii. HCO3- yd CO32- whk wvx.= fjk;a idïm,hl ls' fuu w.h;a
by; fldgfia§ Tfí ms<s;=r;a Ndú;d lr fuu c, idïm,fha we;s
HCO3- yd CO32- idkaøK w;r wkqmd;h fidhkak'
7
06. (a)
1) W;afma%rl ls%hdldrk m%Odk l%u 2la ,shkak'
2) 2 H2O2 2H2O + O2, KI uÕska fukau legf,aä uÕska W;afma%rKh
lrhs'
A - úfhdackh fyd legf,aä ke;s úg isÿjk wdldrh
B - yuqfõ isÿjk wdldrh
C - legf,aä we;s úg isÿjk wldrh my; m%ia:drfha ,l=Kq lrkak'
Yla;sh
m%;sl%shd ldKavdxlh
3) m%;sls%hdj uÕska W;afm%arKh fõ' j, m%;sls%hdj meyeÈ,s lsÍug hdka;%Khla
,shkak'
(b) my; olajd we;af;a wdï,sl udOHfha yd whvhsÜ whk w;r m%;sls%hdfõ iS>%;djh
iïnkaO o;a; iuQyhla fõ'
0'02 moldm-3 H202 0'2 moldm-3 KI 0'2 moldm-3 iS.%;dj
1 0'01 0'01 0'1 1'75 x 10-6 2 0'03 0'01 0'1 5'25 x 10-6 3 0'03 0'02 0'1 1'05 x 10-5 4 0'03 0'02 0'1 1'05 x 10-5
1' m%;sls%hdfõ fõ. m%ldYkh jHq;amkak lrkak'
2' 1 yd 2 mÍlaIK j,g wÞ<j my; m%ia:dr iïmQ¾K lrkak'
0.03
0.02
0.01
[H2O2]
ld,h (t)
S
iS>%;dj
moldm-3S-1
[H2O2]
[H2O2] Uva P
rovinc
e Sips
ara U
dana
& st
uden
tlank
a.com
8
(c) my; tka;e,ams o;a; i,lkak'
wï,h idkaøKh iïu; WÞiSlrk tk;e,amsh a
KJ mol-1
HCl 0'1 -57'3
CH3COOH 0'1 55
H+(aa) 0'1 -57'3
1' by; o;a; fláfhka meyeÈ,s lrkak'
2' CH3COOH(aq) j, iïu; whkSlrk tka;e,amsh fidhkak'
07.
(a) 0.1 moldm-3 HCl yd 0.1 moldm-3 CH3COOH j, 25cm-3-ne.ska f.k 0.1 moldm-3
NaOH iuÕ fjk fjku wkqudmkh lrk ,È' [ Ka (CH3COOH) = 1.6 × 10-5 moldm-3]
1' HCl yd NaOH w;r wkqudmkhg wÞ< iul;d ,laIfha .Kkh lrkak'
2' CH3COOH yd NaOH w;r wkqudmkhg wÞ< ,laIfha w.h fidhkak'
3' by; wkqudmk folg wÞ< úp,kh my; m%ia:drfha i,l=Kq lrkak'
NaOH
pH
1
2
5
1
9
4
3
10
8
6
7
11
12
13
9
4. by; wkqudmk folg wÞ< o¾Yk my; j.=fjka f;dard ,shkak'
o¾Ylh mrdih
fu;s,a jh,Ü 0-1
fu;s,a Tf¾kaÊ 3-4
fn%dau;hsfuda,a íÆ 6-7
*sfkdma;,Ska 9-10
(b) my; wdldrhg f,day folla tlsfkl iam¾Yj we;'
Eǿ Cu+2/Cu = +0.34 v
Eǿ Fe+3/Fe = -0.4 v
1' moaO;sfha isÿúh yels m%;sls%hd i|yd ;=,s; iólrKh ,shkak'
2' moaO;sfha i;H jYfhkau isÿjk m%;sls%hdj fya;= olajñka meyeÈ,s lrkak'
3' Eǿ Zn+2
/Zn = -0.76 v kï by; moaO;sh iuÕ Zn f,dayh iïnkaO l< úg
isÿjk m%;sls%hd ,shkak'
4' wjqreÿ 3lg muK miq by; moaO;sfhka f.k ishqï l=vq njg wUrd ;kql
H2SO4 ødjKhla iuÕ kgjd fmrd .kakd ,È' túg ,efnk fYaIfha ialkaOh
0.635g úh' ,efnk fmrkh 250cm3 olajd ;kql lrk ,È' ;kql ødjKh
25cm3oaú;sl m%udŒ KMNO4 ødjKhla iuÕ wkqudmkh l< úg jeh jQ mßudj
20cm3úh' ødjKfha ;j;a f.k l=vq iuÕ fid,jd by; KMNO4 ødjKh iuÕu
wkqudmkh l< úg jehfjk mßudj 60cm3 úh' by; KMNO4ødjKfha
c,h
F e
C u
2H2O + 02 + 4e 4OH-
Eǿ = +0.4V
Uva P
rovinc
e Sips
ara U
dana
& st
uden
tlank
a.com
10
25cm3iu`. wdï,sl udOHfha m%;sls%hd lsÍug jeh jQ 0.02moldm-3 mßudj
40cm3úh'
i. isÿjk ish¨ m%;sls%hd ;=,s; ridhksl iólrK j,ska bÈßm;a lrkak'
ii. by; moaO;sfha mej;s Fe, Fe2O3 yd Cu m%;sY; fidhkak'
iii. ñY% f,dayh ;kql H2SO4 j, Èh lsÍug wÞ, fya;= bÈßm;a lrkak'
C – fldgi (08,09, 10)
m%Yak follg muKla ms<s;=re imhkak'
08. i. A hkq wldnksl ixfhda.hls'
mÍlaIKh ksÍlaIKh
A ys c,Sh ødjK fldgilg ;kql
wï,h tla lrk ,È' ,d ly wú,;djla ±lsh yel'
A ys c,Sh ødjK fldgilg ys
ødjKh lrk ,o ødjK iaj,amhla
tla lrk ,È'
$ ødjKfha j¾Kh wj¾K úh'
A ys c,Sh ødjK fldgilg
ødjK iaj,amhla tla lrk ,È'
m<uqj iqÿ wjlafIamhla ,nd ÿka w;r
iaj,am fõ,djlska l¨ meye úh'
A >kh iaj,amhlg myka is`t mÍlaIdj
isÿ lrk ,È' oï j¾Kh iys; ±,a,la ,nd ÿks'
fya;= olajñka ixfhda.fhys wvx.= wekdhkh yd legdhkh y÷kd.kak'
ii.my; rEmfha olajd we;s isg olajd ixfhda. j, ridhksl iQ;% ,shkak' fuu
wjlafIamh WKq c,fha ÈhjQ w;r isis,a jQ úg kej; we;s fõ'
11
; HCl l¨
+ +
K3 [ FeCCN)6]
K2CrO(aq) BaCl2(aq)
;Èka
r;a
lsÍu
ÿUqre ly iqÿ
09. (a) ødjKhl wvx.= Fe+2, Fe+3 úYaf,aIKh i|yd my; olajd we;s mshjr wkq.ukh
lrhs'
mshjr 1
Fe+2 yd Fe+3 whk wvx.= x kï ødjKhlska 25.00cm3 la f.k thg
idkaøKh KMnO4 ødjKhlska 75cm3 la tla lrk ,È' tys§ ,enqk
oï meye ødjKfhka 25.00 cm3 la f.k idkaøKh jQ ìhqfrÜgqfõ
we;s Tlai,sia wï,h 75 cm3iuÕ wkqudmkh isÿ lrk ,È' tys§ ,enqk ìhqfrÜgqfõ
mdGdxlh la úh'
mshjr 2
Fe+2 yd Fe+3 whk wvx.= x kï ødjKhka 100 cm3 f.k thg jeämqr SO2 jdhqj
nqnq,kh lrk ,È' tu ødjKfhka 25.00cm3 f.k thg kej; jQ
S (s)
M(aq)
Q(g)
M(s)
T(s)
N(aq) O(s)
R(S)
U(S)
V(aq)
P(aq)
Y(aq)
ÿUqre j,h
FeSO4 / yd H2SO4 ìxÿ lSmhla
ks,a
X(S) W (aa)
Conc. HNO3 ìxÿ lSmhla
ÿUqre
NH4OH(4) ,d ly ÿTqre
Uva P
rovinc
e Sips
ara U
dana
& st
uden
tlank
a.com
12
KMnO4 ødjK 75cm3la tla lrk ,È' túg ,enqK oï meye ødjKfhka 25.00cm3
la iuÕ H2C2O4 wkqudmkh l< úg ìhqfrÜgq mdGdxlh 6.50 cm3 úh'
i. isÿjk ish`tu m%;sls%hd i|yd ;=,s; ridhksl iólrK ,shkak'
ii. ødjKfha wvx.= yd whk idkaøK fjk fjku fidhkak'
10& (a)
1' WKq idkaø NaOH ;=<g whäka l=vq jYfhka tla l< úg olakg ,efnk
ksÍlaIK 3la ,shkak'
2' by; ^1& ys isÿjk m%;sls%hdj ,shkak'
3' by; ^2& ys M,h jYfhka ,efnk ødjKh ìxÿ jYfhka CuSO4 ødjKhg tla
lrk ,È' túg olakg ,efnk ksÍlaIK ,shkak'
4' by; ^3& ys isÿjk m%;sls%hd ,shkak'
5' by; ^3& ødjKh fmrd fmrKhg H2SO4 j,ska wdï,SlrKh lr thg ìxÿ
jYfhka Na2S2O3 tla lrk ,È'
i. olakg ,efnk ksÍlaIK ,shkak'
ii. isÿjk m%;sls%hd ,shkak'
(b) A kue;s ixfhda.hl ixhq;sh my; olajd we;'
Na = 16.67% S = 23.19% O = 57.97%
Na = 23 S = 32 O= 16 H= 1
1' A ys wKqNúl iQ;%h f.dv kÕkak'
2' A ys c,Sh K2CO3 ødjKhla yd tlaj fõ.fhka jdhqj msg lrhs kï y÷kd
.kak'
3' A ye¢kSug wÞ< m%;sls%hd i|yd iólrK ,shkak'
4' A idok wekdhkfha yevh
13
5' A ys mQ¾K ,jKh BaCl2 iuÕ isÿ lrk m%;sls%hdfõ iólrK ,shkak'
(b) A kue;s uQ, øjH B kue;s uQ, øjHh yuqfõ ;Èka r;a l< úg ,efnk C kue;s
ixfhda.h c,fha Èh l< úg j¾Kj;a ødjKhla ,enqKs' th D úh' D j,g KI tla
l< úg ødjKh ÿUqre meyehg m;a jQ w;r E kue;s M,h ,enq‚' E ødjKhg kej;
B tla l< úg kej; D ,enq‚' E j,g c,Sh NH3 jeämqr tla l< úg fld< mdg
wjlafIamhla ,enq‚' D kue;s j¾Khla ødjKhg AgNO3 tla l< úg iqÿ
wjlafIamhla ,enqKq w;r th NH3 j, Èh úh' th F úh'
1' A isg F olajd øjH j, iQ;% ,shkak'
2' isÿjk m%;sls%hd wkqms<sfj,ska ,shkak'
3' D j,g KCN jeämqr tla l< úg ,efnk ksÍlaIK ,shkak'
4' by; ^3& ys ksÍlaIKh wÞ< m%;sls%hdj ,shkak'
5' by; ^3& ys ixfhda.hg D tla l< úg olakg ,efnk ksÍlaIK ,shkak'
6' by; ^5& ys ksÍlaIKhg wÞ< m%;sls%hdj ,shkak'
Uva P
rovinc
e Sips
ara U
dana
& st
uden
tlank
a.com