2020 TJC Qn paper Promo

2 9729 / TJC Promo/ 2020 [Turn over Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet (OMS). 1 The following shows the deflection of two ions in an electric field. Which of the following could be J? A B+11 B Li+7 C Al3+27 D Mg2+24 2 Use of the Data Booklet is relevant to this question. Which of the following species do not have the same number of unpaired electrons as the others? A P+ B Cu3+ C Ca D S Source J x y x > y 16O2– 2020 TJC H2 PROMO MCQ

3 9729 / TJC Promo / 2020 [Turn over 3 Use of the Data Booklet is relevant to this question. Which of the following have the same number of particles as 23.0 g of ethanol, CH3CH2OH, molecules? 1 the number of atoms in 2.125 g of ammonia 2 the number of molecules in 11.35 dm3 of sulfur dioxide at standard temperature and pressure 3 the number of sodium ions in 250 cm3 of 2.0 mol dm-3 sodium carbonate A 1 and 2 B 2 and 3 C 1, 2 and 3 D 2 only 4 Use of the Data Booklet is relevant to this question. A vanadium complex has the formula VO(CxHyOz)2. The percentage composition by mass of the complex is: C, 45.30%; H, 5.29%; O, 30.20%. What is the value of z? A 1 B 2 C 4 D 5 5 The redox reaction between hydrogen sulfide, H 2S, and sulfur dioxide, SO 2, gives elemental sulfur as the only sulfur-containing product. How many moles of sulfur dioxide react with one mole of hydrogen sulfide? A 1 2 B 1 3 C 1 D 2

4 9729 / TJC Promo / 2020 [Turn over 6 Tryptophan is an essential amino acid. Tryptophan What are the approximate bond angles 1, 2 and 3? 1 2 3 A 109.5 90 120 B 120 109.5 120 C 109.5 90 107 D 120 109.5 107 7 The boiling points of ethane and methanal, are as follows: Compound Boiling point /C CH3CH3 Ethane -88.6°C Methanal -19 °C Which of the following statements best explains this difference in boiling points? A Methanal has a larger electron cloud than ethane. B Methanal has a strong C=O bond but not ethane. C Methanal has a permanent dipole but not ethane. D Methanal exhibits intermolecular hydrogen bonding but not ethane. 1 2 3

5 9729 / TJC Promo / 2020 [Turn over 8 Hydrazine, N2H4(l), reacts with dinitrogen tetraoxide, N 2O4(g), to form nitrogen gas and water vapour. 2N2H4(l) + N2O4(g) → 3N2(g) + 4H2O(g) The following data are given. Substance Hfo / kJ mol1 N2H4(l) +50.6 N2O4(g) +9.2 H2O(g) –241.8 What is the enthalpy change for this reaction? A –1077.6 kJ mol–1 B –856.8 kJ mol–1 C –301.6 kJ mol–1 D –182.0 kJ mol–1 9 Sodium burns in oxygen to form Na 2O. Heat energy is given out. The equation for this reaction is shown below. 2Na(s) + ½ O2(g) → Na2O(s) Which of the following statements about the reaction are correct? 1 The magnitude of ∆H○ for the reacti