Chemistry 1 Past Paper 2022 PDF - Tanzania National Examinations Council

THE UNITE D REPUBLIC OF TANZA NIA NATIO NAL EXAMINATIONS COUNCIL OF TANZA NIA CERTI FICATE OF SECONDARY EDUCATION EXAMINATI ON 032/1 CHEMISTRY 1 (For Both Scho...

THE UNITE D REPUBLIC OF TANZA NIA NATIO NAL EXAMINATIONS COUNCIL OF TANZA NIA CERTI FICATE OF SECONDARY EDUCATION EXAMINATI ON 032/1 CHEMISTRY 1 (For Both School and Private Candidates) Time: 3 Hours Year:2 022 Instructions 1. This paper consists of sections A, B and C with a total of fourteen (14) questi ons. 2. Answer all questions in sections A and B and one (1) question from section C. 3. Section A and C carry fifteen (15) marks each and section B carries seventy (70) marks. 4. Non - program mable calculators may be used. 5. Cellular phones and any unauthorised materials are not allowed in the examinat ion room. 6. Write your Examina tion Number on every page of your answer booklet(s). 7. The following constants may be used. Atomic masses: H = 1, C = 12, N = 14, 0 = 16, Na = 23. 23 Avogadr o's number = 6.02 x 10 3 GMV at s.t.p = 22.4 dm 1 Faraday = 96,500 coulombs. 3 3 l litre= J dm = 1000 cm. - ("·.J (".J 0 0 0..,.-f ("·.J Pugc I u l' 4  SECT ION A (15 Marks ) Answe r all questio ns in this section. b l 'or each of th 1· · write its lett er b ,s· d he.tems (I) - (x), choose the correc t answe r from the given alterna tives and ~ - 1 e t e item 11 · b 111 · um er the answe r bookle t provided. Which _is a chemi cal proper ty of water? ( (i) A It IS a very good solven t \ B' I... ' t is nei~her acidi c nor basic. \ C It has higher surfac e tensio n. \ (?'(...___ D It can ex ist in three states of matter. E [t expan ds when it freeze s. ( ii ) of atoms? What is th e maxim um numbe r of electro ns in the innerm ost shell A 3 B 1 C 4 ~ 2 E 8 (i ii) W hat fe ature is essent ial for a good fue l? A H igh speed of contin uous energy supply. ~ High energy value supplied. C L ow carbon dioxid e suppli ed. D High carbon dioxid e produc tion. E High conten t of non-co mbust ible materi al. pollen grains susp ended in (iv) What conclu sion can be draw n from the random movem ent of air? A Matte r is lighter in nature. B Matter is solid in nature. ~. Matte r is particu late in naturt. D Matte r is gaseou s in nature. /y M atter is w ave in nature. (v) Which energy source that can be reused after being exploi ted? A C ombu stible source. B Non-r enewa ble source. ~ R enewa ble source. D Synth etic source. E Natur al source. (vi) W h ich on e is the molec ular formu la for prop-1 -ene? A C3H5 B CH3CCH C C3H4 H- ~ D HCH2CCH ~ CH3CJ ;:\CH2,.:;:: ~.i.-1 _ e: -...C. ·1 1 '! I 1 (vi i) Whi c h o f the fo llow in g is not a compo ri6nt of the F irst Aid Kit? A Gogg les B A pair of sci ssors / Kn ife D Gl oves E Razor b lade (vi ii) Wh ich e le ment is ox idi sed in lhe fo llow ing reac ti o n? 2FcS0 4 +Cl 2 + JI 2 S0 4 -. Fe(S0 4 ) ~ +2HCI. A Chlorine 1lydrogc n C Oxy gen D Su lphur Iron Page 2 of 4 ·r' ',  I · 1- · ,.,. I CL kt 1u sl:111 11 L \\ li1i'h ur the foll)1 '' 1·ng art' t 1c cnmponc11 1s llL' kerosene \ l\ 1atch ho \, fir e'' ood and o\ygen ~ Match box, fire " ood and Oxygen, fue l and fire " ood C D Oxygen, heat and match box E Oxyg en. l'ucl and hea t ation of air? t durin g the fractional distill (x) Why is nitrogen formed firs ft ha s go t low densi ty. li ng po int. B A ft has got high boi g po int. J?1 It ha s go t high density. C It has go t low me ltin point. E It has got low bo iling respo nd ing physical rat e of che m ical rea ctions in Lis t A with the cor Matc h the effect s on the item num ber in the writin g the lett er of the correc t res pon se beside the co nd ition s in Li st B by answ er bo oklet provided. List B Lis t A time L:: A Inc rease in tempera ture (i) Inc reases colliding partic les per B Increase in surface area (ii) Favours endothermic reaction A Increase in pre ssure J C (iii) Inc reases the speed to reach equ ilibrium Jf3 D Increase in con centration (iv) Favours the side wi th fewer mo lecules -ff- E Introducing a catalyst F Decrease in temperature opposite side D (v) Favo urs more products on G Decrease in' pressu re ) SECTION B (70 Ma rks s section. Answer all questions in thi exa mple for eac h. is ma tte r in our dai ly life ? Gi ve four points with an 3. (a) How useful Give three reasons. are the chemi cal sym bo ls important in Chemistry? (b) Why d standing on a direct in a beake r con tai nin g excess dilute sulphuric aci Zinc granu les were placed seconds as 4. ke r and its contents were rec orded after ev ery two of the bea reading balanc e. Th e mass shown in Table 1. Table 1 6 8 10 0 2 4 Ti me (s) 107.20 107.20 110.10 110.00 108.50 Mass (g) 110.20 ss? (a) Why th ere was a Joss in ma ain con stant after the eight seconds? Why did the mass rem s use d instead (b) uld hap pe n to the rate ofr eaction if zinc powder wa (c) Bri efly ex plain what wo of granules. 28 was ana lyzed and fiot ind to be compos ed of 0.6 the mo lec ula r ma ss of. 5. A certain co mp ound with. - 1o hydrog en. g of carbo n and 0. I g of CJ' l t its em pir ica l formu l a and molecular for mula. (a) Wo rk out \o its homo logous ser ies. (b) Classify th e compound lo n( ( 6 ~f-➔ v ~ ') ~ "P ag c3 of X\\ (l, IJ- /4 ' 4 £_' ( (\ µ '2 f' r,( 1·1 ,r, I Jr, ·x-; J 1c~ · Cs'~, 0 r,1 l, 1) 'J v,. I -  sing a pre pn re a ga s in the laboratory hy_dec~mpo t to 1 prepared an experimen through the solution tor 3 hours. \ 111111 I lii l'l' sludcnt ,,a s all ow ed to llm ,\ icit)-. A steady current l11111p1lt111d tistn g1 clectr t was produced. of the ga s wh ich rel ighted the glowing splin \ ts P-+. I 2 dm I ntal set up? t ter mi no log y is us ed to refer to such expe ri me la) Wha , w ing in the circuit. (b) Work out the current flo nitrate, ,,..,:_-,.1 :um ca rb on ate Lead - -. · so lubilit..y m. wa te r ~- · ~ - ' - 7. · C las sif y ti1e r10 II ow mg sa 1ts on the bas is of ad sulph ate. ate , B ;rr nm s_l!_lp hate, Zinc chlori de and Le Si lve r chloride, Co pp er (I!) su lph wa ter of lat h e1. w1·th th 1·ee sa mples of. needed to for m so lution 8. T abl e 2 s11o ws t l1e volume of soap fo ll ow: ta fro m the tab le to an swer the questions that da eq ua l vo lu me s. Use the Ta ble 2 3 I ( cm Volume of Soap Solution ) Water Sample 6.5 E 0.2 F 3.7 G ch da ta e of wa ter tha t mu st be kept co ns tan t for su er than the volum (a) Ide ntify two things oth to be meaningful. I~ l a reason. wa ter sam ple ha s the highest hardness. Give (b) (i) Identify which rdness of water. - I, , (ii) Give three causes of ha e!, chlorine and sugar. fol low ing su bs tan ce s: milk, copper, soap, ~te 9. Consider the , 1, ,. res from the list. nts , comp ~unds and mixtu ( (a) Ide nti fy the ele me I.. t~~ , e1 em fn ~sl' ~e nti fie d in 9(a). J ces between (b) Gi ve four differen 1 1 m its ore. co ke an d ho t air in the extraction of iron fro Explain the function of r po int s. 10. (a) m is a vit al ele me nt in our daily life. Give fou t that aluminiu (b) Account for the fac and a ga s wh ich d wi th dil ute HN 03 an d gave a blue solution en sample was mixe on further he ati ng 11. An unkn~~ n gre ing sol uti on wa s ev ap orated to dryness and up. The result ng splint. precipitated lime water a bro wn ga s which relighted a glowi d tog eth er wi th black residues was forme id and the two gases. the gre en sam ple , blu e solution, the black sol and nitric acid, (a) Identi fy cti on between the green sample ical eq ua tio n for the rea (b) Give balanced chem idues. and the equatio n for the formation of black res points. sh aJk an es fro m alk enes by giving three J 2. (a) Di sting ui rather· tha n oth er e 1em en ts? n giv en sp eci al alt en tion in organic ·chemistry (b) Wh y carbon has bee , Gi.ve fo ur reasons. \, I ' ) SECTION C (15 Marks in lhi s section. An sw vr one (J) ques ti on nza nia.. Ex pl ain six cff cc ls of' walvr po llu tion in Ta J3.. so.I r.,. T.. n ers It>lll,, lln n be ad or lctl by lh e frin. l..1111 , e 1t1 tty 111 Ta nza nia. 14 Desc ribe six wa ys lh al c.i Pa ge 4 or 4.