2024 YIJC JC2 H1 CHEM PE P2 (suggested answers)

©YIJC [Turn over YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CANDIDATE NAME SUGGESTED ANSWERS CG H1 GROUP 1 / 2 / 3 CHEMISTRY Paper 2 Structured and Free Response Questions Candidates answer on the Question Paper. Additional Materials: Data Booklet 8873/02 10 September 2024 2 hours READ THESE INSTRUCTIONS FIRST This document consists of 16 printed pages and 1 blank page. For Examiner’s Use Section A 1 / 9 2 / 8 3 / 10 4 / 10 5 / 12 6 / 11 Section B 7 or 8 / 20 Penalty units significant figures Total / 80 Write your name and class in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all questions. Section B Answer one question. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in brackets [ ] at the end of each question or part question.

©YIJC [Turn over 2 Section A Answer all the questions in this section in the spaces provided. 1 (a) A, B and C are three consecutive period 3 elements in the periodic table. D is an isotope of one of the elements. Table 1.1 shows information on the number of protons, neutrons and electrons in species of A, B, C and D. Table 1.1 species protons neutrons electrons A 15 16 15 B2− 16 17 q C 17 18 17 D− 17 17 18 (i) Deduce the value of q. [1] 18 (ii) Identify the element, A, B or C, that is isotopic to D. Explain your answer. [2] C. They have the same number of protons but different number of neutrons.

©YIJC [Turn over 3 (b) Element E is a Period 3 element. The first nine successive ionisation energies, in kJmol−1, of element E are given in Table 1.2. Table 1.2 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 1251 2298 3822 5159 6542 9362 11018 33604 38600 (i) With reference to E, explain what is meant by first ionisation energy of E. [1] First ionisation energy of E is the energy required to remove one mole of the outermost electrons from one mole of gaseous E atom to form one mole of gaseous E+ cations. (ii) Use the information given in Table 1.2 to deduce the identity of element E. Explain your answer. [2]