AJC H1 chem Paper 1

AJC\H1 chem Paper1\2008 1 Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 0.18 g of a dibasic acid (Mr = 90) is reacted with 0.10 mol dm -3 sodium hydroxide solution. What is the volume of the alkali needed for complete reaction? A 30 cm 3 B 40 cm 3 C 50 cm 3 D 60 cm 3 2 A gaseous organic compound, X, was burnt in an excess of oxygen. A 0.224 dm 3 sample of X, measured at s.t.p., produced 2.2 g of carbon dioxide. How many carbon atoms are there in one molecule of X? A 2 B 3 C 4 D 5 3 If the relative atomic mass of an element which consists of two isotopes 10 M and 11 M is 10.8, what is the percentage of 11 M atoms in the isotopic mixture? A 20 B 50 C 80 D 92 4 Ions of two isotopes of chlorine are 35 Cl - and 37 Cl -. Which one of the following statements is correct? A The 37 Cl - has more protons than 35 Cl -. B The 37 Cl - has more neutrons than 35 Cl -. C The 37 Cl - has more electrons than 35 Cl -. D The electron arrangement of both these ions is 1s 22s 22p 63s 23p 5 5 For whch of the following is the lattice energy likely to have the greatest numerical value (i.e. greatest magnitude, disregarding the sign)? A lithium fluoride C potassium iodide B rubidium chloride D sodium chloride 6 From which of the following reactions can the bond energy of the C—Cl bond be determined by using only the standard enthalpy change of the reaction? A CCl 4 (g) → C(g) + 4Cl(g) B CCl 4 (g) → CCl 2(g) + Cl 2(g) C CCl 4 (g) → C(s) + 2Cl 2(g) D CCl 4 (s) → CCl 4 (g)

AJC\H1 chem Paper1\2008 2 7 Which one of the statements about the properties associated with ionic and covalent substances is correct? A All covalent compounds have low melting points compared to ionic compounds. B Any covalent compound that contain both hydrogen and oxygen in its molecule can form intermolecular hydrogen bonds. C A covalent compound cannot be an electrolyte. D Ionic compounds differ from metals in that ionic compounds do not conduct electricity in the solid state. 8 Which of the following statements best explains why the boiling point of ethanal is higher than that of propane? A The C=O bond in ethanal is stronger than the bonds present in propane molecules. B The dipole-dipole interaction between ethanal molecules is stronger than the Van der Waals forces between propane molecules. C The relative molecular mass of ethanal is higher than that of propane. D The ethanal molecule has a larger surface area than that of propane. 9 V and W can react together to reach equilibrium in the reaction below. V(g) + W(g) X(g) + Y(g) In an experiment, an 1.0 mole each of V and W were reacted at constant pressure P and temperature 350 OC. The amount of Y present in the mixture at intervals of time was recorded. The experiment was repeated at the same pressure P, but at a temperature of 700 oC. The results for both experiments are shown below. time Which one of the following information cannot be deduced from the graph? A The value of K c decreases with an increase in temperature. B The rate at which equilibrium is achieved is faster at higher temperatures. C The enthalpy change for the forward reaction is negative. D The activation energy of the forward reaction is high. number of moles of Y 350 oC; pressure P 700 oC; pressure P 0.2 0.4 0.6 0.8 1.0 0.0

AJC\H1 chem Paper1\2008 3 10 An equilibrium can be represented by the following equation. A(aq) + B(aq) P(aq) + Q(aq) In a certain mixture, the equilibrium concentration of B is 5 mol dm -3 . What will be the new equilibrium concentration of B if 2 mol of pure B is dissolved in the mixture? A 5 mol dm -3 B 7 mol dm -3 C betweeen 5 mol dm -3 and 7 mol dm -3 D between 3 mol dm -3 and 5 mol dm -3 11 What is the pH of the solution formed by mixing equal volumes of two separate portions of aqueous sodium hydroxide of pH 11 and 13? A 11.3 B 12.0 C 12.5 D 12.7 12 What is a satisfactory indicator for the titration of 0.1 mol dm -3 ethanoic acid with 0.1 mol dm -3 aqueous potassium hydroxide? A methyl orange (pH range 3 – 4) B bromothymol blue (pH rang 6 – 8) C phenolpthalein (pH range 8 – 10) D There is no satisfactory indicator. 13 The acid-catalysed iodination of propanone may be investigated by reacting dilute aqueous iodine with solutions containing known concentrations of propanone and acid. The rate can be followed by using a colorimeter to measure the colour intensity of iodine present. CH3COCH3 + I2 CH3COCH2I +HIH+ Why is a large excess of propanone used? A to keep the propanone concentration effectively constant B to prevent the iodine form precipitating out of solution C to buffer the acid concentration D to keep the rate of reaction constant

AJC\H1 chem Paper1\2008 4 14 Benzene is nitrated by a mixture of concentrated nitric acid and concentrated sulphuric acid. When the reaction was carried out in an organic solvent the results shown below were obtained. Expt No. [C 6H 6] / mol dm -3 [HNO 3 ] / mol dm -3 initial rate x 10 4 / mol dm -3 s -1 1 0.30 0.30 1.64 2 0.30 0.60 3.28 3 0.60 0.90 4.92 What is the rate equation for the reaction? A rate = k[C 6H 6] B rate = k[HNO 3 ] C rate = k[C 6H 6] [HNO 3 ] D rate = k[C 6H 6]2 [HNO 3 ] 15 In which of the following substances does chlorine exhibit its highest oxidation state? A PCl 5 B NaClO 3 C ClO 3 F D Cl 2O 16 Sodium thiosulphate is used in the textile industry to remove an excess of chlorine from bleaching processes by reducing it to chloride ions. S 2O3 2- + 4Cl 2 + 5H2O → 2HSO 4 - + 8H + + 8Cl - In this reaction, how many moles of electrons are supplied per mole of thiosulphate? A 2 B 4 C 6 D 8 17 Beryllium resembles aluminium in its chemical properties. Which property of beryllium compounds is unlikely to be correct? A Beryllium oxide can undergo reaction with aqueous sodium hydroxide. B Beryllium chloride can form the dimer Be 2Cl 4 . C Beryllium chloride is an ionic compound. D Beryllium chloride dissolves in water to give an acidic.solution. 18 Which graph best shows the variation of radii of the species indicated? A B C D

AJC\H1 chem Paper1\2008 5 19 The elements xenon (Xe), caesium (Cs) and barium (Ba) are consecutive elements in the Periodic Table. What is the order of their first ionisation energies? least endothermic most endothermic A Xe Ba Cs B Ba Xe Cs C Xe Cs Ba D Cs Ba Xe 20 A hydrocarbon, on heating with an excess of hot concentrated acidified KMnO 4 (aq), produces HO 2CCH 2CH 2COCH 2CH 3 as one of the products. What could the hydrocarbon be? A CH 2CH 3 B CH 2CH 3 CH 3 C CH 2CH 3 D CH 3 CH 2 CH 3 21 The compound terpeneol is commonly found in thinner. CH 3 C CH 3 OH CH 3 What deduction about terpeneol can be made from this structure? A It undergoes oxidation with warm acidified potassium dichromate(VI). B It undergoes dehydration reaction with concentrated H 2SO 4 . C 1 mole of terpeneol reacts with 2 moles of bromine in CCl 4 . D It forms a salt with aqueous sodium hydroxide.

AJC\H1 chem Paper1\2008 6 22 The Russian composer Borodin discovered a reaction in which two ethanal molecules combine to form a compound commonly known as aldol (reaction I). Aldol forms another compound on reacting with reagent Q. I 2CH 3 CHO /barb2right CH 3 CH(OH)CH 2CHO II CH 3 CH(OH)CH 2CHO /barb2right CH 3 COCH 2CO 2H Which of the following best describes