NYGH_2024_S4SIP_Prelim_P2_QP

Class Centre/Index Number Name Preliminary Examination 2024 Secondary 4 CHEMISTRY Paper 2 6092/02 1 hour 45 minutes Friday 23 August 0845 – 1030 No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, register number and class in the spaces at the top of this page. Write in dark blue or black pen. You may use a pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid / tape. Section A (70 marks) Answer all questions. Write your answers in the spaces provided. Section B (10 marks) Answer one question. Write your answers 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 printed on page 24. The use of an approved scientific calculator is expected, where appropriate. Examiner’s Use Paper 1 Paper 2 Total This document consists of 22 printed pages and 2 blank pages. Setter: TC NANYANG GIRLS' HIGH SCHOOL [Turn over

2 Section A Answer all questions. 1 Choose from the following oxides to answer the questions. Al2O3 CO CO2 CaO H2O Na2O SO2 PbO Each oxide may be used once, more than once or not at all. (a) State the oxide which (i) is produced as a result of incomplete combustion of carbon-containing fuels. [1] (ii) reacts with both acid and alkali. [1] (iii) has a simple molecular structure. [1] (iv) has an ion with an oxidation state of +2. [1] (v) conducts electricity when dissolve in water. [1] (vi) is made during the fermentation of glucose solution to make ethanol. [1] (b) Explain how ethanol can be separated from glucose solution in (a)(vi). [2] [Total: 8]

3 [Turn over 2 This question is about compounds that contain phosphorus. (a) The formula for a phosphide ion can be written as 𝑃𝑃31 15 3-. Complete Table 2.1 to show the number of particles in this phosphide ion. Table 2.1 particle number of particles electron neutron proton [1] (b) State why the formula for the phosphide ion is P3- rather than P2- or P4-. [1] (c) Calcium phosphate, Ca3(PO4)2 is a mineral that aids bone development. (i) Explain, in terms of structure and bonding, if you expect calcium phosphate to have a high melting point. [2] (ii) Calcuate the percentage by mass of phosphorus in calcium phosphate. percentage by mass = % [1] [Total: 5]

4 3 Molybdenum is a transition element which is used to make steel that is extremely hard. It exhibits variable oxidation states and can be manufacture by heating together molybdenum(IV) oxide, MoO2, and aluminium. (a) Construct the equation for this reaction. [1] (b) (i) Complete the t