ACSI 2019 Y6 Prelim Paper 3_QP

1 Anglo-Chinese School (Independent) YEAR 6 PRELIMINARY EXAMINATION 2019 INTERNATIONAL BACCALAUREATE DIPLOMA PROGRAMME CHEMISTRY HIGHER LEVEL PAPER 3 Friday 20th September 2019 1 hour 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. • Answer all questions from Section A and Section B 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. • The maximum mark for this examination paper is 45 marks. 0 0 2 3 2 9 For examiner’s use Section A Qn 1 /8 Qn 2 /7 Section B Qn 3 /8 Qn 4 /6 Qn 5 /8 Qn 6 /4 Qn 7 /4 Total /45 Candidate Session Number ________________________________________________________________________ This question paper consists of 12 printed pages including this cover page.

2 Section A Answer all questions. Write your answers in the boxes provided. 1. The educational chart below illustrates the acid-base behaviour of element oxides based on the Pauling electronegativity and oxidation state of the element. Source: “acid-base behaviour of 100 element oxides: Visual and mathematical representations”, Journal of Chemical Education It provides a periodic trend method and a mathematical method to better understand the acid-base behaviour of oxides. The two lines, ABB1 and ABB2, are the lower and upper acid-base behaviour boundaries that are drawn to separate the chart into three areas of basic, amphoteric and acidic oxides and can be mathematically expressed with a set of equations. The bottom line (ABB1) separates the basic oxides from the amphoteric oxides and has the following equation: w1 = −3.8x + 7.93. The top line (ABB2) separates the amphoteric oxides from the acidic oxides and has the following equation: w2 = −3.8x + 12.21. General acid-base behaviour can be calculated for any oxide using the formula: ABB= 3.8x + w where ABB = Acid-base behaviour x = Pauling electronegativity w = oxidation state of element in the oxide The lower boundary line is denoted as ABB1 = 7.93 and the upper boundary line is denoted as ABB2 = 12.21. The calculated ABB value is compared with the ABB1 and ABB2 values corresponding to the boundaries to predict the acid-base behaviour. ABB1 line w1 = −3.8x + 7.93 ABB2 line w2 = −3.8x + 12.21 Oxidation state / w 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 Pauling electronegativity / x

3 (This question continues on the following page.) (Question 1 continued)