ChemistryH2P2questionpaper.docx

1、ChemistryH2P2questionpaper SERANGOON JUNIOR COLLEGE General Certificate of Education Advanced Level Higher 2CANDIDATE NAMECLASS INDEX NUMBER CHEMISTRY 9647/02 , 9746/02Preliminary Examination 23 August 2010Paper 2 Structured Question (SPA) 2 hrs, 1 hr Additional Materials: Data Booklet Writing Paper

2、s Candidates answer on the Question Paper. READ THESE INSTRUCTIONS FIRSTWrite your name and class on all the work you hand in.Write in dark blue or black pen on both sides of the paper.You may use a soft pencil for any diagrams, graphs or rough work.Answer all questions in the space provided.Questio

3、ns 6 is a SPA Planning Question for students taking the 9647 syllabus. You are advised to spend 30 minutes on question 6.At the end of the examination, fasten all your work securely together.The number of marks is given in the brackets at the end of each question or part questions. For Examiners Use

4、1 /122 /123 /124 /125 /126 (P)For 9647 /12TOTALThis document consist of 18 printed pages and NO blank pageAnswer all questions1The graph below shows the first eight successive ionisation energies of X against the order of removal of electrons.(a)From the graph, deduce which group of the periodic tab

5、le does element X belongs to.2.(b)Given that element X is from period 3, identify element X. 1.(c)Write a balanced chemical equation for the formation of the oxide of element X and by means of balanced equations, indicate whether the oxide reacts with aqueous NaOH and HCl (aq).3.(d)Write a balanced

6、chemical equation for the formation of the chloride of element X. 1 . (e)Explain the reactions of the chloride of element X with water. Include all relevant equations.3 . . . . . .(f)Explain whether X or the element below X in the same group will have higher first ionisation energy. 2 . . . .Total:

7、12 marks2Stearic acid is present in animal fats and glucose is present in animal glycogen. The enthalpy change of combustion data of these two compounds are shown in the table below.CompoundStearic acid, C18H36O2 (s)Glucose, C6H12O6 (s)Hc / kJ mol1114002810(a)By comparing the enthalpies of combustio

8、n, comment on the fact that arctic animals store their energy mainly in the form of fats, whereas tropical animals store their energy mainly in the form of glycogen.1 . .(b)By considering the number of lone and bond pair of electrons, draw the Lewis structure and predict the general shapes of the fo

9、llowing molecules or ions:(i)F2O (ii)H3O+4 (c)Architectural and other models are often made from brass (an alloy of copper and zinc). The process of making a brass window frame is as followed:1. The pattern of a window frame is drawn on the brass using a special ink.2. The unprotected brass (not cov

10、ered by ink) is removed by using dilute hydrochloric acid and the outline of the frame remains. With the aid of the Data Booklet, identify the metal that dissolves in dilute hydrochloric acid. Explain your answer.3(d)A heart pacemaker consisting of zinc and platinum electrodes, is implanted into the

11、 body tissues. These electrodes in the oxygen-containing body fluid, with a pH of 7.4, form a cell in which zinc is oxidised and oxygen is reduced.(i)Write a balanced equation for the overall reaction that takes place when a current flows. . (ii)How would the Ecell value change if a human with the h

12、eart pacemaker undergoes a period of intense exercise? Explain your answer.4 . . . . . .Total: 12 marks3(a)To extract titanium from its ore rutile, TiO2, the ore is first mixed with coke and the mixture was reacted with chlorine at 800oC to 1000oC. The reaction yield titanium (IV) chloride gas and c

13、arbon monoxide gas. The next step is the reduction of the chloride by magnesium under a blanket of noble gas. The reduction temperature is at about 850oC to 900oC and a spongy mass of titanium is obtained and the magnesium chloride is tapped off from time to time and recycled.SubstanceMelting point

14、(oC)Titanium (IV) chloride-24.8Titanium oxide1843Magnesium650Magnesium chloride714 (i)Using the data and information given, construct the chemical equations, with state symbols, of the above mentioned procedure. . .(ii)Hence, using the equations in (i), determine the mass of rutile required to produ

15、ce 100 g of titanium metal.3(b)Briefly relate the rate of SN2 reaction of CH3Br with the CH3O- and CH3CO2- nucleophiles.2 . . . . . .(c)Outline possible synthesis for each of the following compounds from the given starting materials. 4(i)CH3CH2COOH to CH3CH2CH2CN(ii)CH3CH2CH2OH to CH3CH2CH(OH)CO2H(d

16、)Suggest methods by which the following compounds could be distinguished from each other using chemical tests. The chemical tests may rely on a preliminary break-up of the compounds and subsequent testing of the reaction products. 3(i)and Chemical Test(s):. .Observations:. . .(ii)and Chemical Test(s

17、):. .Observations:. . .Total: 12 marks4(a)Draw the organic product(s) of each reaction carried out on compound X.Compound XAcidified KMnO4,HeatAqueous NaOH, heat4(b)The diagram below shows a segment of a polypeptide chain Y of a protein.(i)A strand of polypeptide chain would continue to fold further

18、 into structural pattern of alpha-helix or beta-pleated sheets to gain extra stability.Using a clearly labelled diagram, describe the alpha-helix structure. . . . .(ii)Explain why the polypeptide chain Y given in the question will not coil into an alpha helix structure. . . . 3(c)Interpret each of t

19、he following observation as fully as you can. Use diagram or equation(s) in your interpretation if applicable.(i)The relative molecular mass of ethanoic acid in benzene is 120, but measurement of the density of the vapour is consistent with a relative molecular mass of 60. . . . .(ii)The pH of the e

20、nd-point in the titration of ethanoic acid with sodium hydroxide is greater than 7. 5 . . . .Total: 12 marks5(a)Vitamins are essential organic molecules that are essential to the well being of our human health. Four vitamin molecules are given below: Vitamin A Vitamin B7 Vitamin D3 Vitamin K3 (i)State one reagent and condition that will react with vitamin A and not with vitamin K3 and describe what would be observed.Reagent and condition: .Observation: . .(ii)State one reagent and condition, other than oxidising agents that will react with vi