AS CHEMISTRY Paper 1 Inorganic and Physical Chemistry

AS CHEMISTRY Paper 1 Inorganic and Physical Chemistry Tuesday 14 May 2024 Morning Time allowed: 1 hour 30 minutes Materials For this paper you must have: • the Periodic Table/Data Sheet, 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 this 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. • If you need extra space for your answer(s), use the lined pages at the end of this book. Write the question number against your answer(s). • 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 80. Advice You are advised to spend about 65 minutes on Section A and 25 minutes on Section B. Section A Answer all questions in this section. box A student does a series of reactions with aqueous solutions of some potassium halides (P, Q and R) of equal concentration. Each solution contains a different halide ion (chloride, bromide or iodide). The student adds 3 drops of bromine water to 3 drops of each aqueous solution of potassium halide. The student also adds 3 drops of the bromine water to 3 drops of water. Table 1 shows the student’s observations. Table 1 Observation when 3 drops of bromine water are added Solution P Orange solution Solution Q Brown solution Solution R Orange solution Water Orange solution 0 1 . 1 Identify the halide ion present in Q. Give the ionic equation for the reaction that occurs when bromine water is added to Q. [2 marks] Halide ion in Q Ionic equation . Explain, in terms of oxidising ability, why the observations from these reactions do not allow the student to identify the halide ion present in P and the halide ion present in R. box [2 marks] . The student does a second experiment to determine the halide ion in each of P and R. The student adds a few drops of aqueous silver nitrate solution to 2 cm3 of each potassium halide solution. Table 2 shows the student’s observations. Table 2 Student’s Observation P Precipitate formed R Precipitate formed Describe a further chemical test that the student can complete on the precipitates formed to identify the halide ion present in P and the halide ion present in R. Describe how the observations from this test can be used to identify the halide ion present in P and the halide ion present in R. [3 marks] Turn over for the next question Turn over ► This question is about the elements in Group 2. box . Explain why the third ionisation energy of beryllium is much higher than the second ionisation energy of beryllium. [3 marks] 0 2 . 2 Magnesium reacts slowly with cold water but rapidly with steam. Compare these reactions, in terms of the products formed. You should identify one similarity in, and one difference between, these reactions. [2 marks] Similarity Difference . The reaction of calcium with water is a redox reaction. Explain, in terms of oxidation states, why this reaction involves both oxidation and reduction. [2 marks] Turn over for the next question DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box Turn over ► This question is about structure and bonding. box . Define electronegativity. [1 mark] . Explain why the C–Cl bond is polar. [2 marks] . Although the C–Cl bond is polar, CCl4 is a non-polar molecule. Explain why. [2 marks] . There are van der Waals forces between non-polar molecules. Explain what causes these forces. [3 marks] box Barium reacts with oxygen to form barium oxide. Barium oxide has a high melting point and an ionic lattice structure similar to that of sodium chloride. . Draw a 3D diagram to show how the particles are arranged in a barium oxide lattice. You should draw eight particles. [2 marks] *07* Turn over ► A student is provided with separate unlabelled samples of four different solutions for analysis. The four solutions are known to be ammonium nitrate, potassium sulfate, sodium carbonate and magnesium nitrate, but the student does not know which sample is which. Outline a series of test-tube reactions that the student can use to identify each of these solutions. box Include: • the expected observations • ionic equations for any reactions. [6 marks] *0* box Turn over ► SF6 and SF + have different shapes and different bond angles. Deduce the shape of SF6 and the shape of SF + State the bond angle in SF6 and the bond angle in SF + Justify the bond angles by referring to electron pairs. [6 marks] box Turn over for the next question DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box Turn over ► This question is about atomic structure and mass spectrometry. box . Give the full electron configuration for Br [1 mark] A sample of bromine (Br2) is analysed in a mass spectrometer. The sample is ionised using electron impact ionisation. . Give an equation, including state symbols, for the process that occurs during the ionisation of bromine. [1 mark] box . State how the detector enables the relative abundance of each ion to be determined