ACSI 2021 Y6 Prelim Paper 2 QP

1 Anglo-Chinese School (Independent) YEAR 6 PRELIMINARY EXAMINATION 2021 INTERNATIONAL BACCALAUREATE DIPLOMA PROGRAMME CHEMISTRY HIGHER LEVEL PAPER 2 Monday 13th September 2021 2 hours 15 minutes INSTRUCTIONS TO CANDIDATES • Do not open this examination paper until instructed to do so. • Write your candidate session number in the box above. • A calculator is required for this paper. • A copy of the Chemistry Data Booklet is required for this paper. • Write your answers in the boxes provided. • If you use additional sheets of paper for your answer, attach them to the booklet. Indicate the question number clearly on these sheets. For examiner’s use Qn 1 /12 Qn 2 /8 Qn 3 /9 Qn 4 /11 Qn 5 /6 Qn 6 /11 Qn 7 /12 Qn 8 /7 Qn 9 /7 Qn 10 /7 Wrong s.f. /units Total /90 ________________________________________________________________________ This question paper consists of 20 printed pages including this cover page. Candidate Full Name: Candidate Number:

2 Answer all questions. Write your answers in the boxes provided. 1. (a) Sir James Jeans, who was a great populariser of science, once described an atom of carbon consisting of six bees buzzing around a space the size of a football stadium. (i) Explain, in terms of an atom of carbon, what stopped the bees from flying away from the space of the football stadium. [1] ................................................................................................................................... ................................................................................................................................... (ii) State one inadequacy in Jeans’ description when applied to an atom of carbon. [1] ................................................................................................................................... ................................................................................................................................... (b) The graph shows a sketch of the first ionisation energies of seven consecutive elements in Period 2 and 3 of the Periodic Table. The letters are not the symbols of the elements. (This question continues on the following page) First ionisation energy / kJ mol−1 A B C D E F G H I J

3 (Question 1 continued) (i) Explain why the first ionisation energy of C is much lower than that of B. [2] ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... (ii) Sketch on the same axes in (b) for the first ionisation energy trend of the elements H, I and J. [1] (c) A 5.00 g mixture of sodium oxide and sulfur trioxide is dissolved in water to give a pH neutral solution. (i) Write an equation for the reaction of each oxide with water. [2] Sodium oxide: ........................................................................................................... ................................................................................................................................... Sulfur trioxide: ........................................................................................................... ................................................................................................................................... (ii) Determine the mass of sodium oxide in the mixture. [2] ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... (This question continues on the following page)

4 (Question 1 continued) (d) (i) The diagram shows the visible spectrum of a solution of [V(H2O)6]3+. State, giving a reason, the colour of the solution. [1] ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... (ii) [V(H2O)6]3+ reacted with Zn under suitable conditions to form a different colour solution containing [V(H2O)6]2+ and Zn2+. Explain why the solution changed colour. [2] ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... ...................................................................................................................................

5 2. (a) The compounds shown below have similar relative molecular masses. Arrange the following compounds in order of increasing boiling point. CH3CH2CHO, CH3CH2CH2CH3, CH3COOH, CH3CH2CH2NH2. [1] ................................................................................................................................... ................................................................................................................................... (b) Explain the order of boiling points in the compounds you have listed in (a), in terms of intermolecular forces. [3] ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... ................................................................................................................................... (c) Deduce the type of hybridization shown by the nitrogen atoms in NF4+ and N2H2. [2] NF4+: ......................................................................................................................... N2H2: ......................................................................................................................... (d) Describe how sigma () and pi () bonds are formed. [2] ......................................................................