XMS SEC 3 WA3 2023 QP

3 6092/Chemistry/2023 Term 3 Weighted Assessment Section A Answer all questions. Write your answers in the boxes provided at the end of the Section. 1 Which of the following shows the processes used to separate solid potassium nitrate crystals from sand? A dissolve in water → evaporate the filtrate → crystallise → filter B dissolve in water → filter → evaporate the filtrate → crystallise C filter → dissolve in water → evaporate the filtrate → crystallise D filter → evaporate the filtrate → dissolve in water → crystallise 2 Which of the following shows the correct ionic equation for the reaction between dilute nitric acid and zinc metal? A 2H+ + Zn → H2 + Zn2+ B H+ + OH− → H2O C Zn2+ + 2NO3− → Zn(NO3)2 D Zn2+ + 2H+ → H2 + Zn 3 1 Titration of an acid against a base is a method often used in the preparation of salts. 2 3 Which properties of the acid, the base and the salt are required if this method is to be used? acid base salt A insoluble insoluble insoluble B soluble insoluble insoluble C soluble soluble insoluble D soluble soluble soluble 4 A mixture of three liquids is separated by fractional distillation. Which statements are correct? 1 The liquid with the highest boiling point is collected first. 2 The liquid with the lowest boiling point is collected first. 3 The mixture boils at a constant temperature throughout the separation. 4 The temperature at which the mixture boils increases during the separation. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4 4

4 6092/Chemistry/2023 Term 3 Weighted Assessment 5 The table below shows information about three indicators. indicator colour change pH at which colour changes methyl yellow red to yellow 3 bromocresol green yellow to blue 5 thymolphthalein colourless to blue 9 Which one of the following colours would be obtained for each indicator if it were added separately to pure water? methyl yellow bromocresol green thymolphthalein A red blue blue B red yellow blue C yellow blue colourless D yellow yellow colourless Question 1 2 3 4 5 Answer

5 6092/Chemistry/2023 Term 3 Weighted Assessment For Examiner’s Use Section B Answer all questions. Write your answers in the spaces provided. 6 Choose from the following substances to answer the questions. Al2O3 NaCl N2 Pb(NO3)2 SO2 Each substance may be used once, more than once or not at all. Select from the list above, (a) the amphoteric oxide(s). …………………………………………………………………..………………..…… [1] (b) the acidic oxide(s). …………………………………………………………………..………………..…… [1] (c) the compound that will react with dilute hydrochloric acid to form a precipitate. …………………………………………………………………..………………..…… [1] (d) the compound that can be prepared by titration. …………………………………………………………………..………………..…… [1] [Total: 4]

6 6092/Chemistry/2023 Term 3 Weighted Assessment For Examiner’s Use 7 Study the reaction scheme belo