AQA_A_LEVEL CHEMISTRY PAPER 1 2019 GRADED A

A-level CHEMISTRY Paper 1 Inorganic and Physical Chemistry Tuesday 5 June 2019 Afternoon Time allowed: 2 hours For Examiner’s Use Question Mark 1 2 3 4 5 6 7 8 9 10 TOTAL Materials For this paper you must have: • the Periodic Table/Data Booklet, provided as an insert (enclosed) • a ruler with millimetre measurements • a scientific calculator, which you are expected to use where appropriate. Instructions • Use black ink or black ball-point pen. • Fill in the boxes at the top of the page. • Answer all questions. • You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. • All working must be shown. • Do all rough work in this book. Cross through any work you do not want to be marked. Information • The marks for questions are shown in brackets. • The maximum mark for this paper is 105. *jun* IB/M/Jun19/E12 7405/1 Do not write outside the box Answer all questions in the spaces provided. 0 1 This question is about lattice enthalpies. 0 1 . 1 Figure 1 shows a Born–Haber cycle for the formation of magnesium oxide. Complete Figure 1 by writing the missing symbols on the appropriate energy levels. [3 marks] Figure 1 *02* IB/M/Jun19/7405/1 0 1 2 Enthalpy change / kJ mol–1 Enthalpy of formation for magnesium oxide –602 Enthalpy of atomisation for magnesium +150 First ionisation energy for magnesium +736 Second ionisation energy for magnesium +1450 Bond dissociation enthalpy for oxygen +496 First electron affinity for oxygen –142 Second electron affinity for oxygen +844 6 Table 1 contains some thermodynamic data. Table 1 Calculate a value for the enthalpy of lattice formation for magnesium oxide. [3 marks] Enthalpy of lattice formation kJ mol–1 Turn over for the next question *03* 0 2 Nitrogen and hydrogen were mixed in a 1:3 mole ratio and left to reach equilibrium in a flask at a temperature of 550 K. The equation for the reaction between nitrogen and hydrogen is shown. N2(g) + 3H2(g) ⇌ 2NH3(g) 0 2 . 1 When equilibrium was reached, the total pressure in the flask was 150 kPa and the mole fraction of NH3(g) in the mixture was 0.80 Calculate the partial pressure of each gas in this equilibrium mixture. [3 marks] Partial pressure of nitrogen kPa Partial pressure of hydrogen kPa Partial pressure of ammonia kPa 0 2 . 2 Give an expression for the equilibrium constant (Kp) for this reaction. [1 mark] Kp *04*