ACSBR 5 Salts - Assignment

Anglo-Chinese School (Barker Road) A Methodist Institution Founded in 1886 CHEMISTRY DEPARTMENT OF SCIENCE Name: ( ) Class: SEC 3 SALTS – ASSIGNMENT ALEX LEE/2010 PAGE 1 OF 4 PURE/COMBINED Multiple-Choice Questions [20 Marks] TOTAL SCORE / 30 Write in your selected answer for the multiple-choice questions in the boxes provided. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1. Which of the following ionic compounds is the most soluble in water? A calcium carbonate C silver chloride B magnesium sulfate D zinc hydroxide 2. Which of the following ionic compounds is the least soluble in water? A ammonium carbonate C iron(III) chloride B barium sulfate D lead(II) nitrate 3. Which of the following pairs of salts can be separated by adding water and filtering? A barium chloride, lead(II) nitrate C iron(III) sulfate, zinc nitrate B calcium sulfate, silver chloride D magnesium carbonate, lithium iodide 4. Which two pairs of solutions, when mixed, will produce a precipitate? A barium chloride, potassium nitrate C hydrochloric acid, silver nitrate B copper(II) iodide, sodium nitrate D lead(II) nitrate, zinc nitrate 5. Which two pairs of solutions, when mixed, will not produce a precipitate? A ammonium chloride, silver nitrate C lead(II) nitrate, magnesium nitrate B calcium chloride, sulfuric acid D sodium hydroxide, zinc nitrate 6. Which of the following is not an alkali? A ammonium hydroxide C magnesium hydroxide B calcium hydroxide D sodium hydroxide

ALEX LEE/2010 PAGE 2 OF 4 7. An unknown compound X is insoluble in water and reacts with acids to produce a gas. Which of the following is most likely to be X? A aluminium hydroxide C lithium carbonate B copper(II) carbonate D magnesium metal 8. Aqueous solutions of two salts were mixed. A white precipitate was formed, which was filtered off and transferred to another container. A few drops of dilute hydrochloric acid were added to the solid, and effervescence was observed. What could the two salts be? A ammonium carbonate, barium nitrate C barium chloride, magnesium sulfate B copper(II) chloride, silver nitrate D iron(III) sulfate, sodium hydroxide 9. Which of the following salts should be prepared by titration? A calcium sulfate C magnesium nitrate B lithium chloride D silver nitrate 10. Which of the following salts should be prepared by precipitation? A calcium sulfate C magnesium nitrate B lithium chloride D silver nitrate 11. Jeremy wishes to prepare a sample of potassium chloride. Which of the following solutions would not be suitable as a starting reagent? A potassium carbonate C potassium nitrate B potassium hydroxide D hydrochloric acid 12. Which pair of substances can be used in the preparation of zinc sulfate? A aqueous zinc nitrate, aqueous sodium sulfate B zinc metal, dilute sulfuric acid C solid zinc carbonate, aqueous zinc chloride D solid zinc oxide, aqueous ammonium sulfate 13. Which pair of substances can be used in the preparation of iron(II) hydroxide? A aqueous iron(II) chloride, aqueous potassium iodide B aqueous iron(II) nitrate, aqueous sodium hydroxide C dilute iron(II) oxide, dilute hydrochloric acid D solid iron(II) nitrate, potassium hydroxide 14. A student had to prepare a sample of magnesium sulfate. He chose a solid to add to dilute sulfuric acid. The preparation failed. Which solid had he chosen? A magnesium carbonate C magnesium metal B magnesium hydroxide D magnesium nitrate

ALEX LEE/2010 PAGE 3 OF 4 15. Which of the following substances should be added to dilute sulfuric acid to prepare lead(II) sulfate? A aqueous lead(II) nitrate C powdered lead(II) carbonate B lead metal D powdered lead(II) chloride 16. Michelle wishes to prepare a sample of zinc chloride. She executes the following steps: Step 1: Wash and dry and crystals formed. Step 2: Add excess zinc carbonate to the solution. Step 3: Heat the filtrate over an evaporating dish. Step 4: Place some dilute hydrochloric acid into a beaker. Step 5: Filter out the excess solid. In which order should the above steps be carried out? A 4, 2, 5, 3, 1 C 4, 3, 2, 1, 5 B 2, 5, 4, 1, 3 D 4, 2, 3, 5, 1 17. Which one of the following hydroxides does not give a good yield of a salt with dilute hydrochloric acid? A iron(III) hydroxide C magnesium hydroxide B lead(II) hydroxide D zinc hydroxide 18. How can barium sulfate be best be prepared from barium carbonate? A Add dilute nitric acid, followed by potassium sulfate and filter. B Add dilute sulfuric acid and filter. C Add dilute sulfuric acid, followed by potassium sulfate and filter. D Add excess water, followed by dilute nitric acid. 19. Which of the following describes a step in the preparation of aqueous barium chloride? A Add an indicator. C Filter the mixture. B Add barium sulfate. D Heat in evaporating dish. 20. In the preparation of copper(II) sulfate, why is copper metal a poor choice of reactant to add to the dilute sulfuric acid? A A soluble reactant should be used instead. B Copper is a very unreactive metal. C Copper is very expensive. D Metals do not react with acids.

ALEX LEE/2010 PAGE 4 OF 4 Structured Questions [10 Marks] 21. (a) Write chemical equations, including state symbols, for the following precipitation reactions: (i) aqueous barium chloride + dilute sulfuric acid [1] (ii) aqueous potassium hydroxide + aqueous iron(III) sulfate [1] (b) Lead(II) chloride is an insoluble salt, and can be prepared by mixing solutions of lead(II) nitrate and potassium chloride. (i) State the chemical equation, including state symbols, for this reaction. [1] (ii) Outline the steps, after mixing, to obtain a dry sample of the salt. [1] 22. Sodium phosphate, Na3PO4, is a soluble salt, used as a water softener in washing powders. It is prepared by reacting dilute phosphoric acid, H3PO4, with an alkali. (a) Name the alkali that should be used. [1] (b) Give the formulae of the ions present in sodium phosphate. [1] (c) Construct a balanced chemical equation, including state symbols, for the reaction between dilute phosphoric acid and the alkali. [1] (d) Given solutions of phosphoric acid and alkali, a suitable indicator and standard laboratory apparatus, explain how you would prepare an aqueous sample of sodium phosphate. [3] END