Candidate Name Centre Number Candidate Number % > Ce Copyright: Zimbabwe Schoo! Examinations Council, N2019, ZIMBABWE SCHOOL EXAMINATIONS COUNCIL General Certificate of Education Ordinary Level COMBINED SCIENCE 4003/2 PAPER 2 Theory NOVEMBER 2019 SESSION 2 hours Candidates answer on the question paper ‘Additional materials: Calculator (Optional) ‘Allow candidates 5 minutes to count pages before the examination. ‘Tals booklet should not be punched o stapled and pages should not be removed. The Periodic Table is provided on page 20. INSTRUCTIONS TO CANDIDATES Write your name, centre number and candidate number in the spaces at the top. Write your centre and candidate number in the boxes on the top right comer ot every page of this paper. Check if the booklet has all the pages and ask the invigilator for a replacement if there are duplicate or missing pages. Write your answers in the spaces provided on the question paper. Section A ‘Answer all questions. Section B Answer any two questions. Section C Answer any two questions. Section D Answer any two questions, INFORMATION FOR CANDIDATES ‘The number of marks is given in brackets [J at the end of each question, This question paper consists of 20 printed pages, ‘© ZIMSEC N2019 [Turn overCentre Number Candidate Number Candidate Name G 6 Section A Answer all the questions in the spaces provided. 1. (a) _ State any two differences between inhaled and exhaled air. (b) Transpiration is the loss of water through plant leaves. (State any one advantage of transpiration to the plant. (iii) State any two factors which increase the rate of transpiration.Candidate Nam « = Centre Number Candidate Number ) 2 (@) Describe a natural ecosystem, Q] (©) @__ Define the term balanced diet, 2] Gi) Describe the importance of calcium to a pregnant woman. Q] (iil) State the advantage of eating liver. a) 3. (a) Chlorine gas has two types of atoms as shown: $cl and HCl () State the name given to the two types of the chlorine atoms. ol Gi) Calculate the number of neutrons in $8. (b) Chlorine reacts with sodium to form sodium chloride, NaC/. soovanaois [Turn overCentre Number Candidate Number Candidate Name ) ® C 4 type of bonding in sodium chloride. Name the (i) Draw a dot and cross diagram to show the bonding in sodium chloride, 2) ©) State any two physical properties of sodium chloride. 2] 4. (a) Indigestion is caused by too much dilute hydrochloric acid in the stomach. It is cured by ingesting anti-acid tablets. State, with a reason, the acid-base nature of the chemical Present in the anti-acid tablets. acid-base nature reason Q1 ) @ Iron is extracted from an iron compound found in haematite. ‘Name the iron compound in haematite, 0) 400372 N2019ndidate Ni Candidate Name Centre Number Candidate Number > 5 (©) Two other solid raw materials are fed into the blast furnace together with haematite. Name the two raw materials and state a function for each of these materials. raw material function Taw material function (4) 5. (a)__Fig.S.1 shows a stroke in the operation of an engine. Fig.5.1 (i) Identify, giving two reasons, the stroke shown. stroke reason: B) 40032 N2019 [Turn overCentre Number Candidate Number Candidate Name C 6 @) State the role of a fuel injector in a petrol engine. ty (ii) State the role of a carburettor. ty (ii) Explain the advantage of a fuel injector over a carburettor. 2] 6. Fig.6.1 shows part of the design of a solar water heater. thin copper tubing HU ‘copper plate 400372. N2019@ cc Name Centre Number Candidate Number ) 7 (a) sere @ reason, the most suitable place for placing the solar water heater for best results, place [2] (®) _ State, with a reason, the paint colour on the copper plate. colour Teason 2] (© Explain why (i) a thin copper tubing is used, ii) the storage tank isinsulated. Q]8 Section B Answer any two questions in the spaces provided. 7. (a) __ Fig.7.1 shows a sketch diagram to represent double circulation in mammals. Fig.7.1 () _ Deduce the types of circulation represented by cycles X and Y. Cycle X cycle Y Q) (ii) Suggest the reason for differences in the thickness of the walls of chambers C and D.9 Gili) State any three symptoms of malaria. (iv) State a symptom of ebola which is different from symptoms of malaria. () State any two effects of inhaling glue. 1 2 8. (a) _ Fig.8.1 shows a child suffering from a deficiency disease. Fig.8.1 Name the deficiency disease which the child is suffering from. @10 (ii) Describe how the disease named in (i) could be prevented. Q) (b) Describe the route of the sperm from the testis to the oviduct. 4) (©) _ State one advantage of using condoms during sexual intercourse. 1] (@) Define the term fertilisation. 2] (a) _Fig.9.1 shows gaseous exchange in the alveolus of a mammal. sirin ——}__——sirout film of moisture blood 4003/2 N2019 ®Candidate Name « Centre Number Candidate Number i @ ‘Name the gases moving in the directions shown by the arrows R and S. R Ss . (21 (ii) Describe and explain how the alveolus is adapted for gaseous exchange. 4] ))_ Define the terms plasmolysis and turgidity. plasmolysis turgidity (4)12 Section C Answer any two questions in the spaces provided. 10. (a) (i) Define the term arom. Gi) State the two sub-atomic particles found in the nucleus of an atom. 2] (b) Determine the empirical formula of a compound made up of 75% by mass carbon and 25% by mass hydrogen. (4) (c) Sodium hydroxide solution reacts with dilute nitric acid acid to forma salt and water. (State the type of reaction that occurs. ty) (ii) Determine the chemical formula of the salt. 221 400372 N2019Candidate Name Centre Number Candidate Number ec ) 13 11, (a) Outline the stages involved in the extraction of nitrogen from liquid air. (b) Oxygen can be obtained from the electrolysis of acidified water. (i) Name the acid used to acidify the water. (ii) Explain why the water is acidified. 2] (iii) Explain why the volume of oxygen obtained during the electrolysis process is. half that of hydrogen. (iv) State any one use of oxygen.Candidate Name Centre Number Candidate Number € 14 12, Fig.12.1shows the production of sulphuric acid by the contact process. absorption ower vanadium eae |—-o Wyoxide raighecie esx Fig.12.1 (a) @ Name gas X. 0) Gi) State the role of vanadium (V) oxide. 0] Gil Explain why sulphur trioxide is not directly added to water. (2) (iv) Define the terms exothermic and reversible. exothermic 2] (¥) Name the substance which is formed in the absorption tower. 0)b) 15 Ammonium sulphate, (NH,);SO,, is a fertilizer produced from sulphuric acid. Calculate the percentage composition by mass of nitrogen in ammonium sulphate. B)Candidate Name Centre Number Candidate Number 16 Section D Answer any two questions in the spaces provided. 13. (a) Fig.13.1 shows an alternating current (a.c) generator. direction of rotation of coil fixed magnet Fig.13.1 (® Name the parts labelled A and B. A B 2] Gi) Describe how the a.c. generator produces electricity, (4) 400372 N2019jidate Name Candidate Centre Number Candidate Number or 5 17 (ili) Sketch a graph of output voltage of the generator against time. 21 (b) Explain the effect of using stronger magnets on the magnitude of the output voltage. 2] 14. (a) A gear system has ten teeth in the driving gear and thirty teeth in the driven gear. @ — Calculate the velocity ratio, VR, of the gear system. 2] (di) Determine the efficiency of the system if ts mechanical advantage, MA, is 2.Candidate Name Centre Number Candidate Number Dike) [2] (iil) Give any two reasons why the efficiency of a machine is always less than 100%. 1 Q] (iv) State any two ways by which the efficiency of a machine can be improved. (b) State any two types of machines apart from gears. 15. (a) Describe how electricity is generated at a thermal power station. . (4) (b) State any two disadvantages of using coal as a source of fuel for a thermal power station. (©) _ Give the main difference between a thermal power station and a hydroelectric power station. 4003/2 N2019Candidate Name Centre Number Candidate Number 19 (d)__ State the type of energy possessed by water which is in a dam. a) (e) State the Standard International (S.1) unit of energy.20 DATA SHEET The Periodic Table of the Elements Group : x Ww viv wu [wtfo 4 te ~~ = 7 * * al eee ee tt | Be 8 c N ° F Ne ‘ an we foe | me | ome | nee | oe . ‘ , ‘ . » n | m 7 =f = | = | « Na | Mo au} si} P| s | a} w we ee Sea aT he fe, [i » | « « « 3 =|/*» |/e]*° |]. |] « e a»f=sf=].*]. Ko} Se} se] | | er | mn | Fe | co} mi | cu zn | Ga | Ge | as | ge | or | oe gone [een | tree fate | arte | ome | awe | me | ome | mee | ome | oe | ce | omen | oe | Se] Be] Ke on | F 2 a7 | ae aT [a | a |» % lie ower | sere | ma | = |= * = * wo | @ | me] a | = | ow | om | om | aw] wm Rb | sr | ¥ Zr | Nb | Mo | Te | Ru | Rh | pa | ag | ca | in | sn | so] te | T | xe pane | mee | re | meme | ame | ene | nme | name | meen | nme | Oe | con | ue | | Sh] Te] oF | xe 2 os » “ a ee ee a et fa fa fa = | a | a mm | om | wm | wm | wm | | we | wm me a ae cs | Ba | ta | wf | ta | W | Re | Os | ir | pt | av | tg | tt | ph] Bt | po | oat | Rn om fan fam Le [a fe fe a fee [ae fa fe lem fee femme fae fu fae | a Fr | Ra | Ac oe fa [a - a a ne "58-71 Lanthanoid series Ce Pr Nd Pm | sm eu Gd Th Dy Ho &r Tm | Yb iu ‘90-103 Actinoid series coe | pam | marae | romten | seme | towne | commen | tome | onde | vee | ieee | me | we] te Cree eee ef rf ef | ersamrestmicimans [ar a Key |X | Xe ator eymeat Tm} Pa] | Ne | Pe] am | cm | ek) oe | ee | rm | md | No | tr += proton (atomic) Number | go™™" | gpm dae fae foe * wn er - Lo ee fe [on The volume of one mole of any gas is 28 dm’ at room temperature and pressure (r.Lp.)