مدرسة القديسة مريم الكاثوليكية الثانوية - دبي ST. MARY S CATHOLIC HIGH SCHOOL, DUBAI REVISION WORKSHEET YEAR-10 JANUARY 2019 1.Calculate the relative formula mass (Mr) of aluminium sulfate, Al 2 (SO 4 ) 3 Relative atomic masses (Ar): oxygen = 16; aluminium = 27; sulfur = 32 (2) 2.(a) A student investigated the reactions of copper carbonate and copper oxide with dilute hydrochloric acid. In both reactions one of the products is copper chloride. Describe how a sample of copper chloride crystals could be made from copper carbonate and dilute hydrochloric acid. (4) Page 1 of 9
(b)a student wanted to make 11.0 g of copper chloride. The equation for the reaction is CuCO 3 + 2HCl CuCl 2 + H 2 O + CO 2 Relative atomic masses, Ar: H = 1; C = 12; O = 16; Cl = 35.5; Cu = 63.5 Calculate the mass of copper carbonate the student should react with dilute hydrochloric acid to make 11.0 g of copper chloride. (4) Mass of copper carbonate= -------------------------------g 3.A student tested a metal chloride solution with sodium hydroxide solution. A brown precipitate formed. What was the metal ion in the metal chloride solution? (1) Tick one box. Page 2 of 9
4.A flame test is carried out on three metal compounds, X, Y and Z. The diagram shows the apparatus used (a) (i) Suggest two reasons why platinum is a suitable metal to use as the wire in this test (ii) Why should the platinum wire be cleaned between each test? (1) ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- (iii) Why is a luminous Bunsen flame not suitable for carrying out a flame test? (1) --- --- Page 3 of 9
(b)the three metal compounds are also tested separately with three reagents. The reagents used are aqueous acidified silver nitrate aqueous acidified barium chloride aqueous sodium hydroxide The table shows the results of all the tests. (i) Give the name of compound X and of compound Y. (2) compound X ------------------------------------------------------------------------------------------------- compound Y------------------------------------------------------------------------------------------------- (ii) Identify the cation present in compound Z. (1) --- (c) Describe a chemical test, other than heating, that could be used to show that compound Z contains carbonate ions. (3) Test ----- --- Result -- --- --- --- Page 4 of 9
5. A mass of 2.800 g of iron reacts with 5.325 g of chlorine. (i) Calculate the empirical formula of the compound formed. (3) Empirical formula= (ii) Suggest a name for this compound. (1) -- 6. A titration is to be carried out to find the concentration of a solution of sodium hydroxide. The sodium hydroxide solution is titrated with dilute sulfuric acid. The available apparatus includes a burette, a pipette, a funnel, a conical flask and an indicator. (a) State one safety precaution that must be taken when using sodium hydroxide solution and dilute sulfuric acid. (1) --- --- (b) Write the balanced equation for the reaction of dilute sulfuric acid, H 2 SO 4, with sodium hydroxide. (2) --- (c)the results of titrations to determine how much of an acid is required to neutralise a given volume of an alkaline solution are shown in Figure. Page 5 of 9
Two of the titrations in Figure should not be used to calculate the mean volume of acid required. Identify each titration and give a reason why it should not be used in the calculation of the mean. (2) --- --- --- --- (d)describe the experimental procedure to carry out a titration to find the exact volume of sulfuric acid needed to neutralise 25.0 cm 3 of sodium hydroxide solution and obtain pure, dry crystals of sodium sulfate. (6) --- --- --- --- --- --- Page 6 of 9
--- --- --- --- --- --- 7.( a) Figure 1 shows the outer electrons in an atom of the Group 1 element potassium and in an atom of the Group 6 element sulfur. Potassium forms an ionic compound with sulfur. Describe what happens when two atoms of potassium react with one atom of sulfur. Give your answer in terms of electron transfer. Give the formulae of the ions formed. (5) --- --- --- --- --- --- --- --- Page 7 of 9
--- --- The structure of potassium sulfide can be represented using the ball and stick model in Figure 2. (b)the ball and stick model is not a true representation of the structure of potassium sulfide. Give one reason why. (1) --- --- (c)sulfur can also form covalent bonds. Complete the dot and cross diagram to show the covalent bonding in a molecule of hydrogen sulfide. Show the outer shell electrons only. (2) Page 8 of 9
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