2022 DMSS Chem Prelims P2

[Turn over DAMAI SECONDARY SCHOOL Preliminary Examination 2022 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 2 Secondary 4 Express Setter: Ms See Pei Zhen No Additional Materials are required. 6092/02 23 August 2022 1 hour 45 minutes 80 marks READ THESE INSTRUCTIONS FIRST Write your name, index number and class on all the work you hand in. 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 in the spaces provided. Section B Answer all three questions. The last question is in the form either / or. Answer all questions in the spaces provided. The number of marks is given in brackets [ ] at the end of each question or part question. A copy of the Periodic Table is provided on page 20. The use of an approved scientific calculator is expected, where appropriate. For Examiner’s Use Section A / 50 Section B / 30 Total / 80 This document consists of 20 printed pages.

2 Section A Answer all questions in this section in the spaces provided. A1 (a) Select elements from the list to answer the following questions. You may use each element once, more than once or not at all. aluminium astatine chlorine helium manganese neon phosphorus rubidium strontium tin (i) Which of the elements is a diatomic gas at room temperature? ………………………………………………………………………………….. [1] (ii) Which of the elements forms an oxide which reacts with an acid and an alkali separately? ………………………………………………………………………………….. [1] (iii) Which of the elements forms a stable ion of type X2+ ? ………………………………………………………………………………….. [1] (iv) Which of the elements changes the colour of aqueous potassium iodide from colourless to brown? ………………………………………………………………………………….. [1] (v) Which of the elements can have possible oxidation states of +2 and +4? ………………………………………………………………………………….. [1]

3 [Turn over (b) One isotope of rubidium is rubidium-87. State the number of sub-atomic particles found in an ion of rubidium-87. sub-atomic particle number of particles protons neutrons electrons [2] [Total: 7]

4 A2 Fragrance of perfumes spreading around the room is an example of diffusion. (a) Define diffusion. …………………………………………………………………………………………….. …………………………………………………………………………………………. [1] (b) Explain, using kinetic particle theory, why gases diffuse faster than solids and liquids. …………………………………………………………………………………………….. …………………………………………………………………………………………. [2] (c) When colourless phosphine, PH3, and colourless hydrogen iodide, HI, come into contact, a brown solid is formed. PH3 (g) + HI (g) → PH4I (s)