OCR A Jun 2015 Paper 1 Q1

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Answer all the questions. This question is about the elements with atomic numbers between 58 and 70. (a) Cerium, atomic number 58, is a metal. Complete the table to show the relative charge of each particle and the number of each particle found in a 140Ce2+ ion. Relative charge of each particle Number of each particle present in a 140Ce2+ ion Particle proton neutron electron [2] (b) Cerium behaves as a typical metal when it reacts with dilute sulfuric acid to form the salt cerium(III) sulfate and a second product. (i) Identify the second product.[1] (ii) Write the formula of cerium(III) sulfate and, explain what has happened to the cerium in this reaction in terms of the number of electrons transferred. FormulaExplanation[2] (iii) How has a salt been formed in this reaction?[1]OCR 2015<br />
 (c) Europium, atomic number 63, reacts with oxygen at room temperature. 4Eu + 3O2 2Eu2O3 Calculate the volume of oxygen, in cm3, required to fully react with 9.12 g of europium at room temperature and pressure. (d) A compound of thulium, atomic number 69, has the following composition by mass: Volume =cm3 [2] O 30.7% S 15.4% Tm 53.9% (i) State what is meant by the term empirical formula.[1] (ii) Determine the empirical formula of the compound. Show your working. Empirical formula =[2]OCR 2015 Turn over<br />
 (e) Ytterbium, atomic number 70, is the first element in the Periodic Table to have the first four shells full. (i) State the number of electrons in the fourth shell of ytterbium.[1] (ii) How many orbitals are there in the third shell of ytterbium?[1] [Total: 13]OCR 2015<br />

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