Tiêu đề Feb-Mar_2025_9701_12_QP - Crack A Level.pdf ✅

This document has 20 pages. Any blank pages are indicated. IB25 03_9701_12/4RP © UCLES 2025 [Turn over *5478755567* Cambridge International AS & A Level CHEMISTRY 9701/12 Paper 1 Multiple Choice February/March 2025 1 hour 15 minutes You must answer on the multiple choice answer sheet. You will need: Multiple choice answer sheet Soft clean eraser Soft pencil (type B or HB is recommended) INSTRUCTIONS  There are forty questions on this paper. Answer all questions.  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 multiple choice answer sheet.  Follow the instructions on the multiple choice answer sheet.  Write in soft pencil.  Write your name, centre number and candidate number on the multiple choice answer sheet in the spaces provided unless this has been done for you.  Do not use correction fluid.  Do not write on any bar codes.  You may use a calculator. INFORMATION  The total mark for this paper is 40.  Each correct answer will score one mark.  Any rough working should be done on this question paper.  The Periodic Table is printed in the question paper.  Important values, constants and standards are printed in the question paper.
2 © UCLES 2025 9701/12/F/M/25 1 A Boltzmann distribution for a sample of a reacting gas at a constant temperature is shown. The activation energy, EA, for the reaction is marked. Point  shows the number of particles whose energy is equal to the activation energy. The temperature of the sample of gas is decreased. The shape of the distribution curve changes. Which point could show the number of particles whose energy is the same as the activation energy at the new temperature? number of particles energy EA A C B D 2 Crystals of copper(II) nitrate are prepared by adding an excess of malachite to nitric acid. The formula of malachite is Cu(OH)2•CuCO3. (Mr = 221.0) 12.0g of malachite is added to 30.0 cm3 of 1.50moldm–3 nitric acid. Which mass of malachite is left unreacted when the reaction is complete? A 2.05g B 2.49g C 7.03g D 9.51g 3 X and Y are elements from the same group of the Periodic Table. The 5th to 9th ionisation energies for X and Y are shown. ionisation energy / kJmol–1 5th 6th 7th 8th 9th element X 11 020 15 160 17 870 92 040 106 437 element Y 6 540 9 360 11 020 33 360 38 600 Which row identifies elements X and Y? element X element Y A argon neon B chlorine fluorine C fluorine chlorine D neon argon
3 © UCLES 2025 9701/12/F/M/25 [Turn over 4 An ion with a charge of 2– contains 10 electrons and 14 neutrons. What is its nucleon number? A 14 B 22 C 24 D 26 5 The structure of the hormone histamine is shown. H N C H H C C C N C N H H H z H H H y x histamine Which row contains the bond angles x, y and z in histamine in the correct order from the smallest to the largest? smallest bond angle largest bond angle A x y z B y x z C y z x D z y x 6 When an organic acid reacts with an alcohol, a reversible reaction takes place producing an ester and water. 0.40 mol of an organic acid and 0.30mol of an alcohol are mixed and allowed to stand at 25 °C until equilibrium is reached. At equilibrium, 0.20mol of ester is produced. What is the value of the equilibrium constant, Kc, under the conditions used? A 0.33 B 0.50 C 2.0 D 10
4 © UCLES 2025 9701/12/F/M/25 7 Information about two substances is given. substance electrical conductivity effect of adding to water melting point /K P good when solid and when molten reacts vigorously to produce an alkaline solution 454 Q does not conduct in any state reacts vigorously to produce an acidic solution 317 Which row describes the structure and bonding in substances P and Q? P Q A giant metallic simple molecular B simple molecular giant metallic C giant ionic simple molecular D giant metallic giant ionic 8 An excess of zinc reacts with x cm3 of 2.00moldm–3 hydrochloric acid. The gas produced is dried and collected. The gas occupies 1.534dm3 at 101 000Pa and 293K. The gas produced behaves as an ideal gas. What is the value of x? A 31.8 cm3 B 34.7 cm3 C 63.6 cm3 D 69.4 cm3 9 An aqueous solution of hydrogen peroxide is placed in a flask and decomposes, as shown. 2H2O2(aq)  2H2O(l) + O2(g) The total volume of oxygen gas evolved is 180 cm3 after 90 seconds, measured under room conditions. The rate of the reaction is calculated using the equation shown. rate = time change in moles of H2O2 What is the average rate of the reaction, measured in mol min–1, over the duration of the experiment? A 8.33  10–5 B 1.67  10–4 C 0.0050 D 0.010