Greendale 6092/02 Chem Paper 2 QNs Prelim 2024

1 GREENDALE SECONDARY SCHOOL Preliminary Examination 2024 STUDENT NAME CLASS 4 TEACHING GROUP REG. NO CHEMISTRY Paper 2 Student answer on the Question Paper. No Additional Materials are Required. 6092/02 1 hour 45 minutes READ THESE INSTRUCTIONS FIRST Write your name, class, teaching group and register number in the spaces provided above. 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. Write your answers in the spaces provided. Section B 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 32. The use of an approved scientific calculator is expected, where appropriate. This document consists of 32 printed pages. [Turn over

2 Section A Answer all questions. 1 Two chloride salts, iron(II) chloride and lead(II) chloride are made from the same acid but different preparation methods. (a) Complete Table 1.1, in identifying the reactants to prepare iron(II) chloride and lead(II) chloride salts. Table 1.1 salt reactants acid other reactant iron(II) chloride ………………..………………….. iron(II) carbonate lead(II) chloride ………………………………… [2] (b) Use Table 1.1 to name the resulting solution formed during the preparation of lead(II) chloride salt. solution formed: ……………………………………………….…………………….. [1] (c) While preparing iron(II) chloride, a student added one of the reactants in excess. Use Table 1.1 to identify which reactant must be added in excess for the preparation of iron(II) chloride. Explain your reasoning. …….………………………………………………………………………………………. ……..…………………………………………………………………………………… [1] [Total: 4]

3 2 (a) Fig. 2.1 shows the structure of compound A. Fig. 2.1 Compound A can be polymerised. Draw two repeating units of the polymer formed when compound A is polymerised. [1] (b) Poly(ethene) is an example of a polymer that can be recycled. Describe one physical method and one chemical method used to recycle this polymer. physical method ..................................................................................................... ................................................................................................................................ chemical method .................................................................................................... ................................................................................................................................ [2]

4 (c) (i) Fig. 2.2 shows two monomers that react together to produce a polymer. monomer 1 monomer 2 Fig. 2.2 Draw the structure of the repeating unit of the polymer produced from monomers 1 and 2. [1] (ii) The repeating unit for a different polymer is shown in Fig. 2.3. Fig. 2.3 Suggest one similarity and one difference between the monomers used to make this polymer and those used to make the polymer in (c)(i). ………………………………………………………………………………........... ………………………………………………………………………………........... ………………………………………………………………………………………. ..…………………………………………………………………………………..[2] (iii) Name the type of linkage found in the polymer formed in (c)(i) and the polymer shown in Fig. 2.3. polymer formed in (c)(i): …………………………………………………………. polymer shown in Fig. 2.3: ………………………………………………………. [1] [Total: 7] H2N ꟷ (CH2)2 ꟷ NH2 C ꟷ (CH2)4 ꟷ C HO OH O O (CH2)2 O (CH2)4 O O O C C

5 3 Compounds A and B are isomers. Table 3.1 shows some information about the isomers A and B. Table 3.1 isomer description of isomer empirical formula Mr pH of 0.1 mol/dm3 of solution A ü ü ü C2H4O 88 3 B ü û ü C2H4O 88 3 ü ꟷ presence of unit û ꟷ absence of unit (a) Which data in Table 3.1 supports the statement that A and B are isomers? ……………………………………………………………………………………………... …………………………………………………………………………………………...[1] (b) Use the information in Table 3.1 to deduce and draw the structural formula for isomers A and B. Show all atoms and bonds. isomer A isomer B [2] H ꟷ C ꟷ H H ꟷ C ꟷ H H ꟷ C ꟷ O ꟷ O

6 (c) The structure of another isomer of A and B is shown in Fig. 3.1. Fig. 3.1 Draw the displayed formula of the carboxylic acid and the alcohol that react to form the isomer in Fig. 3.1. alcohol carboxylic acid [2] (d) Another compound R is from the same homologous series as isomers A and B. Compound R contains of 62.1% carbon, 10.3% hydrogen and 27.6% oxygen. Deduce the empirical formula of compound R. Show your working. [2] [Total: 7] H ꟷ C ꟷ C ꟷ C ꟷ O ꟷ C ꟷ H H H H H O H H l l l l ll l l

7 4 Fig. 4.1 shows some elements in the Periodic Table. 1 2 13 14 15 16 17 18 Period 2 Li C O F Period 3 Na Cl Period 4 K Br Period 5 Rb I Fig. 4.1 (a) Put a tick (ü) in one box for each row to show whether the following statements about the trends of some of these elements in Fig. 4.1 are true or false. true false Atoms lose electrons more easily down group 1. Melting point decreases from fluorine to iodine. The strongest non-metal oxidising agent is at the top of a group. Metallic character increases across Period 3. [2]

8 (b) Table 4.1 shows information about some of the elements in Period 2. Table 4.1 element melting point /°C electrical conductivity lithium 180.5 good carbon (graphite) 3600 good oxygen -218.8 poor Use ideas about bonding and structure to explain the differences in properties of the elements shown in Table 4.1. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………. [5] [Total: 7]

9 5 Table 5.1 shows some information about the hydrides of elements in Period 3 of the Periodic Table. Read the information and answer the questions that follow. Table 5.1 element metal / non-metal formula of hydride Mr of hydride effect of adding hydride to water Na metal NaH 24 reacts to form H2(g) and an alkaline solution Mg metal MgH2 26 reacts to form H2(g) and an alkaline solution Al metal AlH3 30 reacts to form H2(g) and an alkaline solution Si non-metal SiH4 32 does not react P non-metal PH3 34 reacts to form H2(g) and a slightly alkaline solution S non-metal H2S 34 reacts to form a slightly acidic solution Cl non-metal HCl 36.5 reacts to form an acidic solution (a) Write a balanced chemical equation for the reaction between NaH and water. …………………………………………………………………………………………. [1] (b) A student performs an experiment to test whether some hydrides react with water. He adds each hydride to water and tests the pH of the mixture. Explain how the result shows whether a hydride is a metal hydride or a non-metal hydride. …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………. [1]

10 (c) Draw a ‘dot-and-cross’ diagram to show the bonding in NaH. Show only outer electrons. [2] (d) Explain why sodium hydride can conduct el