AQA A-Level Chemistry Paper 1 – Inorganic and Physical Chemistry Predicted Paper 2023 with marking scheme attached.

AQA A-Level Chemistry Paper 1 – Inorganic and Physical Chemistry Predicted Paper 2023 with marking scheme attached. Name …………………………………………………………………… Date ………………… 2 hours allowed You should have access to the AQA insert (periodic table and data sheet) to help with answering the questions. Grade boundaries These are VERY rough guesses! Getting a C on this paper does not guarantee you the same mark in the exam. • A* - 90 • A – 80 • B – 70 • C – 60 • D – 50 • E - 40 01 The Born Haber cycle below can be used to determine the lattice enthalpy of NaCl. The cycle includes the value for the enthalpy changes of the steps labelled A-F. 01.1 Complete the Born-Haber cycle by adding the species present on the two dotted lines. Include state symbols. [2 marks] Energy change Letter Enthalpy change of atomization of chlorine A Lattice energy of sodium chloride E First electron affinity of chlorine F 01.2 Name the enthalpy changes for the following steps in the Born-Haber cycle. [3 marks] B: C: D: 01.3 Calculate the lattice enthalpy of NaCl. [1 mark] 02 The table below gives the relative abundance of each isotope in the mass spectrum of element X. Mass number of isotope Percentage abundance 54 6.10 56 92.0 57 1.90 02.1 i. Calculate the relative atomic mass of the element X. Give your answer to three significant figures. [2 marks] ii. Identify the element X. [1 mark] 02.2 The isotopes are converted into ions in a spectrometer. They are separated by deflection and then detected. Describe how ions are formed and detected in a time of flight (TOF) mass spectrometer. [4 marks] 02.3 In a TOF mass spectrometer the kinetic energy (KE) of a 56 Fe 2+ ion was 1.562×10-13 J. Calculate the velocity of the ion using the below equation. KE = ½ mv2 (m= mass/kg and v= velocity/ms-1) (Avogadro constant L= 6.022×1023 mol-1) [3 marks] Velocity = ms-1 03 03.1 What is meant by the term ‘buffer solution’? [2 marks] 03.2 A phosphate buffer system contains both Na2HPO4 and NaH2PO4. The following equilibrium is present in the solution. H2PO4- + H2O ⇌ HPO42- + H3O+ i. Explain how a solution containing a mixture of H2PO4- and HPO42- acts as a buffer. [2 marks] ii. Write an expression for the Ka of H2PO4-. [1 mark] iii. 100 cm3 of 0.5 moldm-3 Na2HPO4 and 100 cm3 of 0.3 moldm-3 NaH2PO4 are needed to give a pH of 7.43 in the phosphate buffer system. Calculate the value of Ka. [4 marks] Ka= 03.3 The dissociation of water is reversible reaction. H2O(l) ⇌ H+(aq) + OH- The ionic product of water varies with temperature as shown in the table below. Temperature/°C Kw/ mol2dm-6 25 1.00×10-14 37 2.00×10-14 50 5.48×10-14 i. Write the expression for Kw. [1 mark] ii. The expression for Kw doesn’t include the concentration of water. Explain why? [2 marks] iii. Explain whether the dissociation of water is an exothermic or endothermic process. [1 mark] iv. Calculate the OH- concentration in an aqueous solution of NaOH with a pH of 9.63 at 25°C. Give your answer to two decimal places. [3 marks] H+ concentration = v. Determine the pH of pure water at 37°C. [2 marks] pH = 04 Group 2 metals and their compounds are used commercially in a variety of processes and applications. 04.1 When barium is heated with nitrogen barium nitride is formed. Complete the electron configuration of, [2 marks] Ba2+: Nitride ion: 04.2 Solid barium nitride is reacted with water, forming an alkaline solution (P) and alkaline gas (Q). i. Identify P and Q. P: Q: [2 marks] ii. Write an equation including state symbols for the above reaction. [ 2 marks] 04.3 A compound of barium X, is used in fireworks as an oxidising agent to produce a green colour. The compound X has the percentage composition by mass as follows, Ba (45.1%), Cl (23.4%), O (31.5%) Determine the empirical formula of compound X. [3 marks] Empirical formula =