DANYAL EDUCATION CHIJ ST JOSEPH'S GONVENT SEMESTRAL ASSESSMENT 1. secl /SCr [SA1. lndex Number Class Name SGTENGE (CHEMTSTRY) Secondary 1 Express. 4r!

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1 secl /SCr [SA 75 lndex Number Class Name CHJ ST JOSEPH'S GONVENT SEMESTRAL ASSESSMENT o 0 SGTENGE (CHEMTSTRY) Secondary Express READ THESE NSTRUGTONS FRST Write your index number, class and name on all the work you hand in. Write in dark blue or black pen. Do not use staples, paper clips, highlighters, glue or correction fluid. Thursday, 5 May minutes Section A There are ten questions. Answer all questions. For each question there are four possible answers A, B, C, and D. Choose the one you consider correct and shade your choice in the Multiple Choice Answer Sheet with a 28 pencil. Each correct answer wilt score one mark. A mark will not be deducted for a wrong answer. Section B Answer all questions in the spaces provided. The number of marks is given in brackets [ ] at the end of each question or part question Show all your working on the same page as the rest of the answer. Omission of essential working will result in loss of marks. Electronic calculator may be used in this paper. The total of the marks for this paper is 40. A copy of the Periodic Table is printed on page. Sefter(s) : Ms lzzati Jamil & MrZulkifli This document consists of printed pages. Sec Exp Chemistry/SA/6 FOR EXAMNER'S USE A B Total 4r!

2 secl/scl [SA] 76 2 Section A (0 marks) Answer all questions. Acids are commonly found in the lab. Which of the following labels is found on bottles of acid? A c 2 Jane measured 3 g of sugar and dissolved it in 30 cm3 of water. Which of the following apparatus did she use? A burette and measuring cylinder B beaker and measuring cylinder C electronic balance and beaker D electronic balance and measuring cylinder 3 A gas produced in a chemical reaction can be collected by the set-up shown in the diagram. delivery tube gas B D gas gas jar Some propefties of four gases are given below. Which one cannot be collected by this set-up? gas density of gas compared to air solubility of gas in water A B c D denser less dense denser less dense slightly soluble insoluble very soluble slightly soluble o Sec Exp Chemistry/SA/6 ffurn Over

3 secl/scr [SA] Which of the following statement is not true about mixtures? A Mixtures can be separated by physieal rnethods. B Mixtures can be either a solution or a suspension. C Mixtures have the same properties as its constituents. D Mixtures are made up of two or more substances chemically cornbined together. 5 Baking soda contains the compound, sodium hydrogen carbonate, NaHCOe. How many elements are there in this compound? A4 B5 c6 D7 6 The maximum quantity of solute present in a given volume of solvent represents A solution. B dilution. C saturation. D concentration- 7 Which of these changes would speed up the rate of dissolving the most? size of particles temperature of sunoundings A decrease decrease B decrease increase c increase decrease D tncrease increase A separating funnel is used to separate A two miscible liquids. B two immiscible liquids. G two liquids with similar densities. D two liquids with similar boiling points. Sec Exp Chemistry/SA/6 ffurn Over

4 secl/scr [SA] 78 4 Which of the following methods can be used to show that seawater contains a soluble solid? A evaporation B filtration C magnetic attraction D condensation 0 A mixture containing two solids is added to excess water, stirred and filtered. A blue Given that, filkate and a white residue are obtained after filtrationnrhite resr'due filtrate Determine which two solids were present in the mixture. A WandX B WandY C XandY D XandZ solid colour solubility in water w x Y z blue blue white white Sec Exp Chernistry/SA/6 insoluble soluble insoluble soluble

5 secl/sc! [SA] 79 5 Section B (30 marks) Answer all questions in the spaces provided. f Anna carried out an experiment in the school's Chemistry laboratory. She heated some chemicals as shown in the diagram below. collar banel (a) State the function of the collar in the Bunsen burner. (b) Anna opened the air hole and lighted the Bunsen burner. A loud hissing sound was heard. (i) State the colour and the position of the flame colour: position of flame: (ii) Explain why this is dangerous. Sec Exp ChemistrylsAl/6 tl tl tl For Examrner's Use

6 secl/scr [SA] 80 2 Magnesium ribbon was added to different volumes of hydrochloric acid. The volume of hydrogen gas produced was measured at regular time intervals and the results were plotted as shown in the graph below. 60 volume of gas / cm { time / min (a) Suggest which curve represents the reaction with the greater volume of hydrochloric acid used. /t (b) (i) ldentify the independent variable in the experiment. (ii) ldentifu the dependent variable in the experiment. (c) A student wanted to investigate the effect of the mass of metal used on the volume of hydrogen gas produced. (i) Suggest a hypothesis for this experiment. A B Sec'l Exp Chemistry/SA/6 t t J l Fq Examiner's Use

7 secl /SCr [SA 8 (ii) Briefly describe how the student can carry out an experiment to test her hypothesis. 3 The following shows the set-up and describes an experiment in which magnesium was heated in air. 7 crucible magnesium ribbon (coiled up) pipe clay triangle tripocl Bunsen burner heatproof mat. Magnesium is a grey metal. A piece magnesium ribbon was placed in a crucible and weighed. 2. The crucible was heated and the magnesium ribbon was burnt with a very bright flame. 3. A white solid consisting of magnesium oxide and a smalt amount of magnesium nitride was formed. 4. The white solid and crucible were weighed. (a) ln this experiment, identify: (i) an element:... (ii) two compounds: (iii) a mixture: Sec Exp Chemislry/SA/6 3l l 2l tl ffurn Over For Examinet's Use i i i

8 secl/scr [sa] 82 (b) State the evidences to indicate that a chemical change has taken place, 4 When an electric current is passed through water, HzO, it breaks down into two gases. One of the gases formed is oxygen. The experimental set-up is shown below. oxygen (a) ldentify the other gas produced from this reaction. (b) Explain how this experiment shows that water is a compound. (c) ldentify which Group and Period oxygen is in Group: Period i{-o, 8 Sec E:p Chemislry/SAll6 battery + l2l tl tl tl For Examiner's Use

9 secl/scr [SA] 83 5 (a) Coppe(ll) sulfate is highly soluble in water. A student accidentally mixed iron fillings, coppe(ll) sulfate and sand. Describe how you would obtain a pure dry sample of coppe(ll) sulfate crystals. (b) Sugar cannot be obtained from sugar solution by evaporation to dryness. (i) What would happen if sugar solution was evaporated to dryness? (ii) Name the method best used to obtain sugar from sugar sotution. (iii) Explain why sugar cannot be separated from its solution by filtration method. Sec Exp Chemistry/SAli6 t4l tl l t2) For Examiner's Use

10 secl/scr [SA] 84 6 The graph below shows the solubility of various substances in water. 0 Su ga r ( ;al t Temperalure ("C) (a) State the relationship between the mass of sugar dissolved and the temperature. o G o e o o o o lr) a G gl s zsa 2AA (b) lf a sugar solution at 70oC was cooled to 20oC, determine the amount of sugar that will crystallise out. Show your working clearly. Mass of sugar that will crystalise out:.g (c) lf have a sugar solution at 00oC, suggest the temperature should cool it down to, in order to get about 2509 sugar crystals. Show your working clearly. Temperature to cool down to: END OF PAPER Sec'l Exp Chemistry/SAli6 tl tl oc t [Turn Over For Examiner's Use

11 secl/scr [SA] 87 Sec Exp SA 206 Science Ghemistry Question Answer D D c D,A Question Answer C B B A c (a) Collan To rgqulate/controlthe flow of s!ildg.the barel (b) (i) Colour: sreen Position of flame: At the air holg. of the Bunsen bumer/ on the jg[ (ii) strike-back would occur / flame.is extr_qf_nelv/verv hot. 2 (a) Curve B (b) (i) volume of acid (ii) volume of gas prod uced (c) (i) the greater the mass of -maglesjgn used, the greater the volume of hlrdroqen qas produced. (ii) ) Measure out S0cm3(qqual volume) of acid with the same/equal concentration) m 2) Add S(gif.t%9nt_Amoun!) of magnesium metalto the q.qid (must statg_that metal is added to acid) 3) lvleasure the volume of hydrogen gas produced. (preferably correctly identify use of gas syringe for measurement; or displacement of water method for cqryparison) Do not accepl upward/downward delivery rnethod. 3 3 (a) (i) magnesium/ oxygen/ nitrogen (ii) magnesium oxide and magnesium nitride 2 (iii) white solid / air {b) the crucible was heated and it bumt with a bright flarne. Magnesium was grey in colour but the product was white in colour 4 (a) hydrogen (b) Water can be broken down by chemical methods (passing electricity through it) (Reject Chemically combined) (c) Group: Vl, Period:2 Group number must be written in roman numerals Sec 2 Exp Chemistry/SA/6

12 secl/scr [SA] (a) ) magnetic attraction/aw 2) dissolution/ add waterl AW 3) filter/filtration 4) identify residue and filtrate 5) heat filtrate till saturation/half the solution 6) crystallization/ coolto form crystals 7) filter crystals/ collecv pick crystals 8) wash and dry with filter paper 2 points mark OR (no magnetic attraction) ) dissolution/ add water/ AW 2) sand and iron are insoluble but copper (ll) sulfate is soluble 3) filter/filtration 4) identify residue and filtrate 5) heat filtrate till saturationihalf the solution 6) crystallizatlon/ coolto form crystals 7) filter crystals/ collecu pick crystals B) wash and dry with filter paper 2 points mark ( b r (i) crystallization (ii) it will decotrydqqg (qqqlqelqed): te chemical change (ii) Sugar is sgluble in water tt= purti"t and thus are able to pass through the filter paper. 6 the the more rnass of dissolves c) 225 g Working (extrapolate from graph given) : At 70oC, 3259 solute /00mlwater At 20oC, 2009 solute/00mlwater Hence, q solutei l00mlwater d at as 47 at Sec 2 Exp Chemistry/CTl6