SULIT SKEMA SBP2010 MARKING SCHEME FOR CHEMISTRY PAPER 2. No Rubric Mark 1(a)(i) Gas 1

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1 SULIT 454 SKEMA SBP00 MARKING SEME FOR EMISTRY PAPER No Rubric Mark (a)(i) Gas (ii) (b)(i) The melting point and boiling point of substance X is lower than room temperature. - X and Y axes are labelled and have unit - correct curve. Boiling point / 66 O is marked on the graph. Temperature / O B.P / 66 O Time / s (ii) Liquid and gas (c). The attraction force between particle in Z is stronger than Y. More heat energy is needed to overcome the attraction force between the particle (d) Melting point is the temperature at which solid change into liquid (e) TOTAL ak ipta Sekolah Berasrama Penuh SULIT

2 SULIT No Rubric Mark (a)(i) ontact process (ii) sulphuric acid (iii) (b)(i) (ii). Formula of reactant and product correct. Balanced SO + O SO. Sulphonation. Neutralisation O ( ) O S O - O hydrophobic part hydrophilic part (iii). ard water contains calcium ions and magnesium ions. React with soap to form scum // React with detergent to form soluble substance/ do not form scum TOTAL 9 No Rubric Mark (a)(i) Solvent P: Water Solvent Q: methyl benzene / propanone / suitable organic solvent (ii) Effervescence / gas released // magnesium ribbon dissolved (iii). Ethanoic acid is weak acid. Ethanoic acid dissociate / ionise partially in water. produce low concentration of + ion (b)(i). p value increase / bigger. The lower the concentration of acid the higher the p value (ii) (0.5)(V) = (0.04)(50) // V = 0 cm V TOTAL ak ipta Sekolah Berasrama Penuh SULIT

3 SULIT No 4(a) (b)(i) (ii) (iii) Rubric Zinc sulphate / nitrate and sodium / potassium / ammonium carbonate // carbonic acid Zinc oxide Yellow when hot, white when cold. Functional diagram. Label Mark Zinc carbonate eat Lime water (c)(i) (ii) ZnO + l Znl + O. eat the solution until saturated.. ool the saturated solution.. Filter and dry by pressing between two filter papers. TOTAL 0 No 5(a)(i) (ii) (iii) (b) (c) olouless solution of potassium bromide change to brown Potassium bromide / bromide ion. orrect formula of reactant and product. Balanced Br - Br + e Purple. hlorine water. hlorine accept Rubric / receive electron Mark (d) 0 to - (e) Acidified potassium manganate(vii) solution // any oxidising agent ak ipta Sekolah Berasrama Penuh SULIT

4 SULIT (f). Functional apparatus. Label G Iron(II) sulphate Ferum(II) sulfat Bromine water Air bromin Sulphuric acid Asid sulfurik TOTAL No Rubric Mark 6(a). Functional apparatus. Label thermometer opper can water Spirit lamp propanol (b). orrect formula of reactant and product. Balanced 7 O + 9O 6O + 8 O (c)(i) eat release = 00 X 4. X = 6040 J ak ipta Sekolah Berasrama Penuh SULIT

5 SULIT (ii) Mole = // (iii) = 0.04 = kjmol - (iv). arrow upward with energy label and two level. exothermic reaction and correct formula of reactant and product Energy 7 O + 9O 6O + 8 O (d) Use wind shield // weight the spirit lamp right after the flame is put off // stir the water continuously TOTAL Num. Answer Mark 7(a)(i). Electron arrangement.8. Total Mark (a)(ii). Group. Period. orrect formula of reactants. orrect formula of product X + Y XY. Electron arrangement of atom Y is Atom X loses two electron to form X + ion 5. Atom Y gains one electron to form Y - ion 6. to achieve octec electron arrangement 7. X + ion and Y - ion attracted to each other by strong electrostatic force / ionic bond ak ipta Sekolah Berasrama Penuh SULIT

6 SULIT (b). Lead(II) bromide cannot conduct electricity in the solid state. Ions do not move freely. Lead(II) bromide can conduct electricity in molten state 4. Ions can move freely 5. Naphthalene cannot conduct electricity in solid and molten state 6. No free moving ions // exist as molecules atode 7. Formula of reactants and product correct 8. Balanced Anode Pb + + e Pb 9. Formula of reactant and products correct 0.Balanced Br - Br + e 0 TOTAL 0 Num. Answer Mark 8(a) ompound X Total Mark Propene + ompound Y O O Propanoic acid ak ipta Sekolah Berasrama Penuh SULIT

7 SULIT ompound Z O O Propyl ethanoate + 6 (b) (c). Dehydration reaction. Add bromine // potassium manganate (VII) solution. Brown colour of bromine decolourised // purple colour of KMnO 4 change to colourless. orrect formula of reactant. orrect formula of product 6 + O 7 O. ondition needed for the reaction: (d) (e) - Phosphoric acid - Temperature 00 O - Pressure 60 atm. Pour cm of glacial ethanoic acid in a boiling tube. Add cm of propan--ol to the acid. Slowly and carefully add concentrated sulphuric acid 4. eat the mixture. Functional group : carboxyl group / - OO. General formula: n n+ OO. orrect formula of reactant and product 4. Balanced 5 OO + ao a( 5 OO) + O + O 4 4 TOTAL ak ipta Sekolah Berasrama Penuh SULIT

8 SULIT Num. Answer Mark 9(a)(i). lean the metals with sand paper. Total Mark. Pour copper(ii) sulphate solution / any suitable electrolyte into a beaker.. Dip a pair of Q and R strips into the beaker. 4. onnect the metals by using connecting wires to a voltmeter. 5. Record the voltmeter reading 6. Determine the negative terminal of the cell. 7. Repeat steps 6 by replacing the pair of Q and R strips with other pairs of metals as shown in the table. 8. The negative terminal metal located higher than the other metal.in the electrochemical series // Q is placed higher than R, R is placed higher than S and P is placed higher than S in the electrochemical series 9. Pair of metals which produced the biggest potential difference located the furthest in electrochemical series // P and S has the biggest potential difference indicate the pair of metal located furthest apart in the Electrochemical series. (a)(ii) (b) 0 P, Q, R, S Electropositivity decrease. Value of x =.6 V. y = P. P is magnesium / metals that is higher than zinc in electrochemical series 4. P / Mg is more electropositive than Q / Zn // P / Mg is higher than Q / Zn in electrochemical series.0 mol dm - sodium chloride 0 4. hloride / l - ions discharged at the anode ak ipta Sekolah Berasrama Penuh SULIT

9 SULIT 454. oncentration of l - ions is higher than + ions. hlorine gas is released mol dm - sodium chloride 4. + ions discharged at the anode 5. + ions is lower than l - ions in electrochemical series 6. ydrogen gas which is colourless released 6 TOTAL 0 Num. Answer Mark 0(a)(i). Experiment I, Experiment III, Experiment II Rate of reaction increase Total Mark. Experiment I and II: Temperature. Experiment II and III: oncentration 4. orrect formula of reactant and product 5. Balanced 5 (a)(ii) (b) l + Na S O Nal + SO + S + O. The concentration of hydrochloric acid in Exp III is higher. The number of particles per unit volume in Exp III is higher compare to Exp II. The frequency of collision between hydrogen ions and thiosulphate ions increases in Exp III 4. Frequency of effective collision increases 5. The rate of reaction increases in Exp III compare to Exp II Temperature Factor [Experiment II] Procedure:. 50cm of 0.moldm - sodium thiosulphate solution is poured into conical flask ak ipta Sekolah Berasrama Penuh SULIT

10 SULIT 454. The initial temperature of the solution is recorded. The conical flask is placed on top of white paper with mark X at the centre 4. 5cm of 0.moldm - hydrochloric acid is poured quickly into conical flask 5. The stopwatch is started immediately 6. The conical flask is swirled 7. The stopwatch is stopped immediately once the mark X disappeared from sight and the time is recorded 8. The experiment is repeated using 50cm of 0.moldm - sodium thiosulphate solution using different temperature, 5 0, 40 0, 45 0 and 50 0 Observation: 9. Yellow precipitate Ionic equation: S O - SO + S + O 0 OR oncentration Factor [Experiment III] Procedure:. 50cm of 0.moldm - sodium thiosulphate solution is poured into conical flask. The conical flask is placed on top of white paper with mark X at the centre. 5cm of.0 moldm - hydrochloric acid is poured quickly into conical flask 4. The stopwatch is started immediately 5. The conical flask is swirled 6. The stopwatch is stopped immediately once the mark X disappeared from sight ak ipta Sekolah Berasrama Penuh SULIT

11 SULIT The time required for mark X disappeared from sight is recorded 8. The experiment is repeated using different volume of 0.moldm - sodium thiosulphate solution with different volume of distilled water Observation: 9. Yellow precipitate Ionic equation: S O - SO + S + O TOTAL ak ipta Sekolah Berasrama Penuh SULIT

12 SULIT Marking Scheme Paper SKEMA SBP00 Qn. No. Marking Scheme Marks (a) Able to state the hypothesis accurately.. Metal which is lower down in Group is more reactive towards oxygen// X is more reactive than sodium and lithium towards oxygen. Able to state the inference less accurately.. Reactivity towards oxygen increases when going down Group //Sodium is more reactive than lithium towards oxygen. Able to state the idea of inference.. Metal can react with oxygen Wrong or no response 0 (b) Able to record the observation correctly.. Metal X burns more vigorously and produces white fumes. Able to record the observation less correctly.. Metal X burns vigorously and produces white fumes. Able to state an idea of the observation. Metal X burns in oxygen/produces white fumes. Wrong or no response 0 (c) Able to construct a table with the following aspects correctly. Title. Observations : Set Observations I Lithium burns slowly and produces white fumes. II Sodium burns vigorously and produces whites fumes. III Metal X burns vigorously and produces whites fumes. Able to construct a table less accurately : I Lithium burns slowly and produces white fumes. II Sodium burns vigorously and produces whites fumes. III Metal X burns vigorously and produces whites fumes. Able to state an idea to construct a table. : Set Observations ak ipta Sekolah Berasrama Penuh SULIT

13 SULIT Qn. No Marking Scheme Marks (d) Able to predict metal X accurately. Potassium Able to predict metal X less accurately Rubidium Able to give an idea to predict metal X. Francium//aesium Wrong or no response 0 (e) Able to record the p meter readings to one decimal place. Set I:. Set II:.7 Set III:.9 Able to record the p meter readings or at least p readings accurately. Set I:.45 Set II:.65 Set III:.9 Able to record at least p meter readings accurately. Wrong or no response 0 (f) Able to give six statements correctly. s 6 Manipulated variable: Types of solution//lithium hydroxide, Sodium hydroxide, Potassium hydroxide. Responding variable: p meter readings//p values Fixed variable: p meter Method to manipulate the variable: Use different solution for each reading/experiment ow the variable is responding: p meter shows different readings with different solutions. Method to maintain the fixed variable: Use same p meter for each solution. Able to give five statements correctly. 5 Able to give four statements correctly. 4 Able to give three statements correctly. Able to give two statements correctly. Able to give one statement correctly. Wrong or no response ak ipta Sekolah Berasrama Penuh SULIT

14 SULIT Qn No. Marking Scheme Marks (a) Able to state the inference correctly. : Iron nail coiled with magnesium does not rust//iron nail coiled with copper will rust Able to state the inference less accurately. Metals in contact with iron nail caused rusting Able to state an idea of inference. Iron nail rusts/does not rust. Wrong or no response. 0 (b) Able to give the operational definition of rusting correctly.. When iron nail coiled with a less electropositive metal /copper is dipped in gelatine added with potassium hexacyanoferrate(iii) and phenolphthalein, dark colouration formed. Able to give the operational definition of rusting less accurately.. Iron nail coiled with a less electropositive metal/copper gives blue coloration// When iron nail coiled with a less electropositive metal is dipped in gelatine added with potassium hexacyanoferrate(iii) and phenolphthalein will rust. Able to give an idea of operational definition of rusting.. Iron nail coiled with copper undergoes rusting. Wrong or no response. 0 (c) (d) Able to give all four correct answers Oxidation: Reduction:, 4, 4 Able to give three correct answers Able to give two correct answers Wrong or no response. 0 Able to classify the four metals correctly. Metals that make iron to rust: Zinc, Aluminium Metals that do not make/prevent iron to rust: Tin, silver Able to classify three metals correctly Able to classify correctly but wrong headings// Able to classify two metals correctly. Wrong or no response ak ipta Sekolah Berasrama Penuh SULIT

15 SULIT Qn. Marking Scheme No. (a) Able to state the problem statement correctly. Does size of zinc affects the rate of reaction with sulphuric acid? Able to state the problem statement less accurately. Does size of zinc affects rate of reaction?// To investigate the effect of size of zinc on the rate of reaction with sulphuric acid. Able to give an idea of problem statement.. Size affects rate of reaction Marks (b) (c) (d) Able to make a hypothesis correctly. When the size of zinc is smaller, the rate of reaction increases Able to make a hypothesis less accurately. Rate of reaction increases when size of zinc decreases.//smaller zinc particles affects rate of reaction Able to give an idea of making a hypothesis. Size affects rate of reaction Wrong or no response 0 Able to state all the three variables correctly Manipulated variable: size of zinc //zinc granules and zinc powder Responding variable: rate of reaction// time taken to collect a fixed volume of hydrogen gas Fixed variable: volume /concentration of sulphuric acid//sulphuric acid Able to state two variables correctly Able to state one variable correctly Wrong or no response 0 Able to list the apparatus and materials completely Apparatus: conical flask 50 ml, burette, basin, delivery tube with stopper, stop watch, triple beam balance, measuring cylinder Materials: zinc granules, zinc powder, [0.-.0] mol dm - sulphuric acid Able to list the apparatus and materials less completely Apparatus: conical flask, burette, basin, stop watch Materials: zinc granules/powder, sulphuric acid Able to list an idea of the apparatus and materials Zinc, [any container], sulphuric acid, stop watch Wrong or no response ak ipta Sekolah Berasrama Penuh SULIT

16 SULIT Qn. No. (e) Marking Scheme Able to list the steps of the procedures correctly s. 50 cm of sulphuric acid is measured using a measuring cylinder and poured into a conical flask.. A burette filled with water is inverted over in a basin of water. Record the initial reading of the burette. 4. Put in 5 g of zinc granules into the conical flask 5. Attach the delivery tube with the end of the tube inserted into the burette. 6. Immediately start the stop watch. 7. Swirl the conical flask and record the burette reading at every 0 s intervals. 8. Repeat steps 6 by replacing the zinc granules with zinc powder Able to list the steps of the procedures less accurately Steps,,4,6,7,8 Able to list an idea of procedures Steps. Sulphuric acid is poured into [any container]. Zinc is added into acid. Marks Wrong or no response 0 (f) Able to tabulate data correctly with the following aspects:. Title with correct units. At least 4 time intervals Time/s Initial burette reading/cm Volume of gas/cm Able to tabulate data less accurately with the following aspects: Time Volume of gas Wrong or no response 0 END OF MARKING SEME ak ipta Sekolah Berasrama Penuh SULIT

PAPER 1 PAPER 2 PAPER 3

PAPER 1 PAPER 2 PAPER 3 BAHAGIAN PENGURUSAN SEKOLAH BERASRAMA PENUH DAN SEKOLAH KECEMERLANGAN KEMENTERIAN PELAJARAN MALAYSIA CHEMISTRY TRIAL-EXAM SPM 0 MARKING SCHEME PAPER PAPER PAPER 3 SKEMA KERTAS PENTAKSIRAN DIAGNOSTIK AKADEMIK