' EXAMlNATJON 032 'l CHElVIJ STRY (for s :1',ool ...

'1{ .J� l" rN11"'"E1 · l{El'UBl.,lC OF TANZANIA TJ() . E r A l\·1INA1

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10NS COUN1ClL

1�1�1·1tr1 , TE OF SECOND .. ·\R\' .EDUCATION EXAMlNATJON

032 'l CHElVIJ�STRY 1

(for s�:1',ool Candiclate.s Oulyj

Tl� IE: 3 l{Olll'S T11esdoy, 6111 Oclober1009 p.111.

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5.

I11�trnctions •

This. pnp.er consists of.section� A. B and C.

;\"ns,,er nU ques1ions in sectioris A and B,. and hvo (2) qttestions n·om section C.

EJectToni..:- calculators .and celllilar pho11es are not allo"ved in the examination room. •

\"\rtite you, Exa1nination: Nun1ber on eve1-;y page ofy,our ans\ver b.ooklet(s).

The :follo,Yin!! const�nts inav be used: .... .,

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.A:ton1ic 1110.sses: H = 1. C = l '. 0 = 16. Na = 23. S = 32, Ca= 40. Cu= 63.5. . ., '

Avn�adr.o 's Nt1111ber = 6.02 X 1 o..;._, .....

it

Givr\' at s.1.p. = 21.4 qm-.

1 Faraday ::::: 9-6.500 touJon,bs.

Stanclar<l pres.sure = 760 n11n Hg.

Standard tQn1perature = ·,73 K.

l litte = l dir/ = l OOOcn1 1•

·rh11 i1aper�unsists of8 printed pages.

Find more free learning resources at; www.darasaletu.com

I

._ J •c� r I {l N \ ( 2 (\ l n r It�)

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t 111 Thl· fo II o,.vi ng sc::t o i'laborutoT�' equq�n1erns. cons I sls ,,I volurnc 1neasu ri 11� i Lcrns.\ Beeik�r, balance. n1easurll1g cyl, n<ler

B Bttreue. pipefte: thern,n111eter

c Btu·ette. pipette� n1easuring cylirrcler

D c,,Jinder can. balance. ,·oluu,etri� 11ask� .... pantla. l1.1ru1cl. conicfil 11a�k.

(iii� .\n anh)tdrotts salt X (relati·ve n1oleculru· 111ass = l 06) \Viti combine ,vitb \vater to futm hytlr3.ted salt X.yI-f1 0. It is fcrnnd that 2 l.2g of X con1bine ,�id\36g of\Vctter. \\;haL is \he value 0f v in tht"- llV"clrated �a 1 t? A 2

B � C 8 D 10 E 12.

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(iv) Which ,0f the tb\lov,ing is true about ioniG con1pounds?A The.)' are easily vapourize<l B They easily dissolve in organic �olvents C They are electronically ne�1tral D Tht}r are all poor conduttors or i:lectricity E They fom, covalent bonds '\Vith triu1sitiu11 cutions.

(Y) l>rtcJpitation can be ri:prcscntccl bv lhe tollov;ing eqttntion:A lf'�iiq, + 01 rH,q1 > I i::�Ou,8 ROI-{ + Jl COOI-f > J{ (�<)<)R 4· li!<1C

D

BaSO.il'ilN!ll'l�lll,,

lKClh., +

r I I


\\ l I ,\ iH1.:l p1 ,up 01 ,rga111c 1.::,,111p(1t111,I•= {111.: p1C"p .. 1r1.·d h> Lhl;! dLh) lt \IL •h • 1 U 1 •

�t\t'tt'!-.fl('l'dtng al ·.!)hul1 \ �, lk rnes

I� \ I ��ni;: ( t\lknnl!,'-D F.�!QI ,� Cnrl,o�� J ic �1cids.

('\�l) h 1�1Jl11ble ,:,�l\L;; lik.e huriun1 ulphrtt<:. gen'1ndly c�1n be obtained in 1hc lr1b�riillQl)' hyf\ eV .. TJ.'ltll'rlltOll vi' i1s c:<-111cenlruh..:(1 !-':blutjon 13 c,,,,tull i'Z�ll ion

..

C D E

precipitation (jc�1..1n1JlO�i t ion tlecrephath)n.

�viii);\ n1ixt11re ofa liquid and insoll1bh.: po,vcler \vhich ltns nut sellled clo\vn is Cftli.i!d u /A sol utr B suspe;J1si<.'Hl C SLll\ enl D condcnsale E rei;;idu�.

(Xi) r"r-1e satne currt:nL passing- (hro'\.lgh solutions of t4e sau1e toncentrnt1c1ns. of sih. �r rutrute rind copp'er sulphate, l1ber�les 0.23 g of silver (equiYalent ,veight = 10�,. The \ve1g.ht of copper (equivnle11r \veight = 31.8) that will be l1beral�ct ,vill be . .\ J 1 .8 g:

B O 0677 Q �

C O ')"__ _, g

D 0.()33 � E 3J 80 t1.

(x) \\'hich of lh.e follo,ving met;.11$ is most ductile?A f\lu1niniun1 B Si Ive, C Copper D ·rin

E Me1·tury

3


u, '

I (')

I t,,i) I (•·iil (,·iii)

tix)

(X)

Chloro 1luor(1c-0rbons

iVLg 1,nd ..

Ufen

Top rl1es�ing

Rec\ cHTH:! of 50Jid n1aterials. -

Cro�1 J·atntion

C�l-i 10.-n .!.. 1101q,t> � 7C01(gi + 8H20111

4

1

f3

C

D

J�

I·

G

FJ

T

• r

K

I�

NI

N

0

p

r I

'

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Burning tit �o I

Ai rtficuat lc.r[Jli l'

ivlt\(.; rt."lli11 If ti ell t

Rcn10, t: le11tpu1111·) harclnc�� 01\.vuter

Au pollution

�'fanaging the loss of plants

nH lrients n·on1 lhe soil

tJ11trented se,vatre ;;;;,

l\.JJ i cro n t1 tri.:nts

Pre\rentiag terrestrial poJJution

I-las plec1sar1t rnste due tl) the

diss,:d ved con1pot1nd.s

Fertilizer ::q,plica.tion rneuhod

Bumi n.g of Jlerro I

Rerno,,es pern1an�nt h::trdne ·s cf

,vater

Les� ·1-'�1' i useJ tor\\ l;:,h1n_�

Has Jour t�).Src tlu� t the: on:, . .J'!c:<-' I

Iof dissof, ep actd

t Pr·occss of ohtu1n1n , elf])l tu,.J

�---=

---


r-

( )

(n)

(b)

(c)

). �a)

\ns,,\."1 :,11 qu-.:�11nn..;; in Hue-:. �t·Ctir1n.

\V11v does11 t ,,ut�r ha, 1.; �11,\ etJt::'..:t t111 lil - .. n1u!:,.; pai,er'1 2 nl.u·k"') (i) '\\ hut \\'rJuld h,,ppC'll lo� ,vc-U �lopper bottle ft,11 0f ..

fa ':¢2.er ll".· �1.nigh1f') ,�,.h� docs th is hni,Jxn'.' \\:a�e.r tc.tl &n 8 daep

{ii) ,� .. t1) 1sn t ,�-on ltsuall-" &"COOt11u1enc{�d in Lhe constn, -· f r 1pcs ln(1 Dllllers? 'E._xplniu.

cnon o. steam

ti)

\ii)

(4 murl·s)

Nau1e t\VO in1.1s ,vhich cause \elllpora:rv hri.rA-es� 0r 't!l .... tb... d . . " uu :-. r Jtl .:.l ""4· an t\VO l G ns ,vh1eh tause· pel'1n�111enl hnr<lne s.

Give equntians for t,vo ,va}s to re1ncrve temporary hurdn�s of ,vater PJld one \\U} to re1110,1e pern1r1ne11t hnrdness. (4 marks)

0.01 tntde� of electrons \\ere passed through a solution of sodiun1 hvrlr.ozcide: ttsing platinunl e.l�ctrodes. (�) Gi,..: the nanies of the gases evolve{l a1 each electrode, (ii) \\"rite ionic equati(Jns of the rea�tio11 tak:iP..g place nr the electrodes.(iii) Calculnte tl1e number of n1oles of ettl:h gas produced and the volume

,vhich each gas ,vould occup)' at S.T.P. (6 mark$)

\'That n,ass of co1)per ,y1ll be liberated during electrolysis of copper sulphate solu1ion b}· ii tl1arge of on� rarada)r'? (J mark)

An elentent X hns a relntive ftlttrn1ic mass oi� 88. \Vheu a cu1Ten1 of O.SJ-\ ivaspas�ed tl1rougb the l\rsed rhloride ofX for 3 ° minutes 10 second�. O.!J.!lg ofX:\'1 as clepo;:;, tetl at th� en th ode. . _ (i'l Calculate (be nurub�r of furaclays needed to lil.icrate l n1ole ot X.

,(ii) V/1:i te the rc.)f111L\ln .for the X !Oll.

(1ii) \\7nLe the formula lb1 hydroxide·ofX. (3 n1arks)

Ho,1r can the rotes of chen1ical r.c::iction::; be inc.re.i.,:sed? factor$

•

Describe :it least tour (Jma�)


lb)

J l

( ' 11 I ii I'"\\ '-i ) lla: lt11lr.v.;ing n1tXLU�.

\\then vrner ax1d kel'osene ,11·e n1ixecl iq the sun1e contnint:r. �vhich one tbm}';

thi: upper lny�r.�' Giv� rcnsfJng, (4 n1�1rJ( )

Dcs,ribe the effect of . .

(i) stt\)ng.ly heating ti �1ece _ o 1· 111�l'bl� 1n :1 Bunsen bu1 nc:r tiarne

(ii) 111oisteni.ng the rt:s1dLte lrotn (1) apo,·e "·'\Jth \Voter. (4 01arks)

(i) l i.i)

For,, hat reaso11 is slaked lime aclded Lo the soil in the gard�ning·:, \V11, is eonceTitrateJ sulphuric acid uset.� as a dr,-}'in!! <l�ent" . .. -

{4 marks)

\\Th,· is zine used as a coat for iron and not, ice ·versn? (2 marks) . - .

8. Table l shc·�·s a part of period· G wbrc "vitl1 ntou1ic nun1bers fr,')n1 J to i 8 �un1eelements are sho,vn bv letters but the letters. are not rh� u·u� S\n11buls ot 1h-c �len:1enb. -

StuJ3 it then ans,ver the questiruis that fullo,\.

(a)

·rable l

bu 1-! . p

-r I

f\,

�n1ong tht! t!lcn1en1s letLered K to Q. ,,·hic11 one (t) ls a haloeen . . ...,.

l!�) i� a 11n bb1� gn::,. (iu) \\ould re<'ltt nla.;t rendilv ,,ith chl "1 ine'.

�

10 �rrJ

IS

(3 rn:1rks)

�cute whetlict lhr: bonding ,n the c't'<ide 01�0 a1ld P ,v,11 be- 101ui.. ,r i;in afent.t l'Casc)ns tor your 8'1S\\;t:t ( .l 11141 rksl

( t ·- ' ( 0

•


tc)

Stutl· lbc 1lll1•--'\\Ytll£. ln\i..S .. \ 1) t,o �·le�.$ lmv

(u) \.J 1.11•1c· � la\\

• \ , rdurne ot' s,tOcn,� ol gns \.Vns �ollootcd at 5ll6°<_'

,,rcssurc. \\th.1t ,,o,1HJ be Lhe volurf1c ul S.T.P'! I

(3 rnnr�J

n ncl 2 all'rltlbTJhe'nt; (3 n1ut·J,-J

1 r the gas 111 tb) ttbovc ,vHS c0lletled iron1 Lhe co111plete th�r1ncrl decompo�11io11 of cnlc1 u111 ,earl ,onate� 1i) \Yha1 is lhe nu,nc ol Lhe gas? lii l ,, hu1 rn_µ.ss c,f talcil1n1 carbon�tle prodt1ced this ,unullnt of gas?

14 nntrks)

10. tn) Briefly explniri each of the tol\ci,,1ing: (i) S l)tl p I--l( ii ) Ba�i_r soiJ \ 1 i i1 T �n acing

• lb� The ,,e1gl1 t of a liesh soil sa.inple fron1 a school farm \vus 55�Tn. 11\e �n1ple

,v:i� tt'rietl in an oven. oL 200cC. cooled in a deSictators and re'-ve,�hed. The ...

,veighr. of the sample. aftel cooling to constant ,veight was 46 �m. � hal ,;vas the percentage of \vater in the soi.I sample? (5111arks)

{i) (ii)

List al teasr t\Vo chen1ical substances Used to neu(rn.lize soil .:icid. Why <lo \Ve classify 11iLrogen as a 111-0cronu11ient in regarJ.ing plants· nut1ief1ts'"' (1 m�rks)

11. The preparacion (if an1\nonia in t.be lnbora1or:y i�s dQne b� heating a mi..xrure ota111n1oniu1n chloride and sotliu1n hyclroxhle.

( i I (ii)

(fl (ti)

\V tire a halanc,e<l che111ica 1 � uarlot1 for the ob�YV1..� 1-et1clion. Using balan�ed �heo11cul equations. state; ho,\ atn111011i�'l re:it{'ts \Vtd1

hytirog-en chloride gas and heated !.:'.Opper £11) n:'ride. \4 ,nn rks)

Snnc t\VQ uses or ununonil'I. Nnn te lhe catul y.st us\!d in rl1e p1't'fnn·ution of nrn,n(•nia. { 2 rn3 rks)

<cJ l:.xpl,tin oacb of th.c foll.o\ving rc.LLction�. givit1� ohser\"ath,ns nnc! equatton�. (1) Agit\!OUS n1-n1nunia ,s :added to irrin tlll) chl(H1 id �. Hule b) li1tle. \Jntil

!,!'X:CC-"'S

Sod'iiun uilmte is strongly neact:d .

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(h) ·1:;cn1) of (l soiuli.(JJ1 G011tai11ing 0. l 96g c�f a Jlletnl hyclrr1xide Yor-.r� -- trnlizem by J5cin1

i,f o <l. J 1\nl h} drocl1lor1c acid solution� ocu · b 1 d f · • l · 1· h i) ,,rril� do\vn n :i an�e c 1:011cn tj'll!,1t1on o� t e reaction.

tii) Colcttlale the n1alnr1t)' of 111e b;·drox1dc solullon, liH) Calruhue the rel ad \'-e rnoJecular n1ass of YOH (6 rn:itrks)

le) Ka 1ue rhe i11dicator )·on \Vould clroose for the follo\ving tiltarions-:(i) h}rdrt1cl1Ioric: acid ,,,ersus runn1on ia sollHjon

(ii) uct'tic acid ,,er.sus socli un1 J1)'drox ide (1 rnfirk)

\.Vere


' EXAMlNATJON 032 'l CHElVIJ STRY (for s :1',ool ...

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