1. Which of the following elements has the highest percentage by mass in nature? A. Oxygen B. Aluminium C. Nitrogen D. Silicon

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1 Class: F.3 ( ) Baptist Lui Ming Choi Secondary School First Term Examination ( ) Date: 6 / 12 / 2013 Name: Form 3 Chemistry Time: 10:20-11:05 a.m. Answer ALL the questions. For Section A, choose the best option and write the correct answer on the multiple choice answer sheet. For other sections, write the correct answers on the answer sheets provided. Section A: Multiple Choice Questions (20%) 1. Which of the following elements has the highest percentage by mass in nature? A. Oxygen B. Aluminium C. Nitrogen D. Silicon 2. Which of the following is NOT true for a compound? A. The composition by mass of the constituent elements is fixed. B. Heat is usually given out or absorbed when the compound is formed. C. Properties are entirely different from those of the constituent elements. D. Constituent elements can be separated by physical methods such as distillation. 3. Which of the following statements is true for a mixture of alcohol and water? A. Alcohol can be separated out by fractional distillation. B. Water can be separated out using separating funnel because it is denser than alcohol. C. The mixture is an example of immiscible liquids. D. Alcohol has higher boiling point than water. 4. Which of the following is NOT a physical change? A. Ice melts. B. Water boils to become steam. C. Carbon burns in oxygen. D. Dry ice sublimes to become carbon dioxide gas. 5. Which of the following is NOT the major source of chemicals in the planet Earth? A. The oceans B. The atmosphere C. The inner core of the Earth D. The Earth s crust P.T.O.

2 Form 3 Chemistry P.2 6. Which of the following statements is true about iron sulphide? A. It can be attracted by a bar magnet. B. A gas with bad egg smell is given out when dilute acid is added to it. C. It floats on water. D. It is very soluble in water. 7. Which of the following is the industrial method of manufacturing oxygen? A. Electrolysis of water B. Fractional distillation of liquid air C. Photosynthesis D. Heating copper(ii) oxide 8. Nitrogen is very useful (1) in food packaging to prevent unwanted reactions caused by air. (2) as a refrigerant for storing things at a very low temperature. (3) in making ammonia for further production of fertilizers. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1),(2) and (3) 9. Which of the following gases is used to fill advertising lights nowadays? A. Helium B. Hydrogen C. Neon D. Air 10. Which of the following statements concerning a saturated salt solution is correct? A. The amount of salt dissolved in the solvent is maximum at a particular temperature. B. The boiling point of the solution is lower than 100 C. C. Salt in the solution can be extracted by filtration. D. The solution is so concentrated that it forms crystals at room temperature quickly. 11. A student places some sea water on a watch glass and heats the sample with a steam-bath. Which of the following would be observed after 20 minutes? A. Black solids appear and float on the surface of sea water. B. The sea water becomes milky. C. The volume of the sea water increases. D. White powder is left on the watch glass. To be continued

3 Form 3 Chemistry P Sea water was once a source of drinking water in Hong Kong, because A. sea water contains minerals that are good for our health. B. water can be distilled out from the sea water. C. the amount of salt in sea water at that time was so low that sea water could be used as drinking water. D. the taste of sea water matched people s preference at that time. 13. Which of the following apparatus is NOT required during the filtration of sea water? A. Filter funnel B. Glass rod C. Condenser D. Filter paper 14. Which of the following substances is NOT one of the major products in the electrolysis of brine? A. Potassium hydroxide B. Chlorine C. Hydrogen D. Sodium hydroxide 15. A large amount of sodium chloride is found in sea water. Which of the following methods can be used to extract pure water from sea water? A. Filtration B. Distillation C. Crystallization D. Sublimation 16. Which of the following statements is NOT true about clean air? A. It is colourless. B. It is needed for rusting of iron to occur. C. It is explosive. D. The most abundant element in air is nitrogen. 17. Hydrogen is a product from electrolysis of sea water. Which of the following are the uses of hydrogen? (1) Manufacture of hydrochloric acid (2) Manufacture of nitrogenous fertilizers (3) Fuels for space shuttles A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1),(2) and (3) P.T.O.

4 Form 3 Chemistry P Which of the following statements is INCORRECT? (1) If a sample turns dry cobalt chloride paper pink, the sample is pure water. (2) If a sample contains chloride ions, gas bubbles are given out when excess dilute nitric acid and silver nitrate solution are added to the sample. (3) In a flame test, dilute hydrochloric acid is used to moisten the platinum wire. A. (1) and (2) B. (1) and (3) C. (2) and (3) D. (1),(2) and (3) 19. Which of the following concerning oxygen gas is correct? (1) It is slightly soluble in water. (2) It is flammable. (3) It causes rusting of iron. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1),(2) and (3) 20. The hazard warning label shown below is found on a container. Which of the following substances may be stored in the container? A. Hydrogen B. Chlorine C. Oxygen D. Carbon dioxide Section B: True or False (10%) Choose the best option and put a in the box provided. 1. Salt solution is a mixture of elements. 2. Nitrogen gas is used to make soft drink. 3. Heat is given out when steam is converted to water. 4. Argon is used to fill the light bulb 5. Water is used to put out fire when alcohol catches fire. 6. Town gas is poisonous because of the presence of carbon dioxide gas. 7. Gas with bad egg smell is given out when dilute acid is added to iron. 8. Water turns hydrated copper sulphate crystal from white to blue. 9. Chemistry is the study of various substances, about their structures, properties and the changes among them. 10. The atmosphere is important because it protects living things from the high-energy radiations from outer space. To be continued

5 Form 3 Chemistry P.5 Section C: Matching (10%) In the boxes provided, write the letters in column II that match with the numbers in column I. Column I Column II 1. Copper metal A. Group 0 in periodic table 2. Benzene B. An element which is ductile 3. Neon C. Gas-liquid mixture 4. Distillation D. Separation of solute from the solution 5. Colloid E. Carcinogenic 6. Dilute sodium hydroxide solution F. Oxidizing 7. Noble gases G. Separation of solvent from the solution 8. Explosion of town gas H. An element which can sublime 9. Beer I. Used in making ammonia 10. Crystallization J. Solution with much bigger particles K. Used in advertising signs. L. Chemical change M. Used in making soap Section D: Fill in the blanks (10%) 1. The following hazard warning labels are displayed on the bottle of ammonia gas, It means that ammonia gas is (a) and (b). 2. Silver oxide is a (c) of silver and (d). It can be broken down into its constituent elements using (e) or heat. 3. Sugar solution is a mixture in which sugar is a (f) while (g) is a solvent. 4. (h) is a gaseous layer (about 80km thick) surrounding the Earth. 5. The major compounds in clean air are (i) and (j). P.T.O.

6 Form 3 Chemistry P.6 Section E: Structured Questions (50%) 1. Air consists of oxygen and other substances. (a) Is oxygen an element or a compound? Explain briefly. (2%) (b) (i) What is the most abundant element in air? (ii) Why the gas stated in part (b)(i) is used to fill food packaging? (2%) (c) (i) Name the method used to obtain pure oxygen and the element stated in part (b) from air. (ii) Explain briefly why oxygen and the element in (b)(i) can be obtained by this method. (iii) Does the method in (c)(i) involve physical or chemical change? Explain briefly. (4%) (d) Suggest a test which allows you to distinguish between oxygen and the element in (b)(i). In your answer, different observations of the test for these two elements must be given. (3%) (e) State the hazard warning label that should be displayed on a jar containing pure oxygen. (1%) 2. Metal W is the most abundant metal in nature which is commonly used to make soft-drink can. (a) What is metal W? (1%) (b) The metal W is strong and corrosion resistant. Give three more physical properties of this metal. (3%) (c) Suggest another daily use of the metal W. (1%) (d) The metal W reacts with oxygen gas in air. (i) Complete the following word equation of the reaction: + oxygen (ii) Is the reaction between the metal W and oxygen a physical change or physical change? Explain. (3%) 3. (a) Dry ice can be used to keep things cold. (i) Give a chemical name of dry ice. (ii) Why is it called dry ice? (iii) State TWO observable changes when a cube of dry ice is put into a beaker of warm water? (4%) (b) Table salt is used as seasoning in our daily life. (i) Name the constituent elements in table salt. (ii) Suggest another use of table salt in our daily life. (iii) What is the main source of table salt in nature? (iv) Name the methods used to obtain pure table salt from (iii) in school laboratory. (6%) To be continued

7 Form 3 Chemistry P.7 4. The results of tests 1-3 with substances A and B are summarized in the following table: Substance Test 1: Flame test Test 2: Addition of silver nitrate solution, followed by excess dilute acid P A Brick-red flame White precipitate is formed B Lilac flame No observable change (a) (i) According to test 1, what metal ions are present in A and B respectively? (ii) State one safety precaution when you carry out flame test. (3%) (b) (i) What is acid P? (ii) According to test 2, name the ion present in substance A. (iii) Name the white precipitate formed in test 2. (iv) Write a word equation to show the formation of white precipitate in test 2. (4%) 5. Consider the following flowchart. (a) Name the physical process shown above. (1%) (b) (i) Suggest what gas Y might be. (ii) Suggest a chemical test of gas Y. In your answer, observable change in the test must be given. (iii) State one common use of gas Y. (4%) (c) Suggest a chemical test of chlorine gas. In your answer, observable change in the test must be given. (4%) (d) Draw a labeled diagram to show how pure water can be obtained from sea water. (3%) END OF PAPER

8 Class: F.3 ( ) Baptist Lui Ming Choi Secondary School First Term Examination ( ) Name: Form 3 Chemistry Score: /100 Section A: Multiple Choice Questions (20%) Mark the correct answer on the multiple choice answer sheet provided. Section B: True or False (10%) Put a in the boxes to show the correct answer T F Section C: Matching (10%) Column I Column II Section D: Fill in the blanks (10%) 1. (a) (b) 2. (c) (d) (e) 3. (f) (g) 4. (h) 5. (i) (j) Section E: Structural Questions (50%) 1. (a) (2) (b) (i) (1) (ii) (2) (c) (i) (1) (ii) (1) (iii) (2) (d) (3) (e) (1) P.T.O.

9 Form 3 Chemistry P.2 2. (a) (1) (b) (3) (c) (1) (d) (i) + oxygen (1) (ii) (2) 3. (a) (i) (1) (ii) (1) (iii) (2) (b) (i) (2) (ii) (1) (iii) (1) (iv) (2) 4. (a) (i) A: B: (2) (ii) (1) (b) (i) (1) (ii) (1) (iii) (1) (iv) (2) To be continued

10 Form 3 Chemistry P.3 5. (a) (1) (b) (i) (1) (ii) (2) (iii) (1) (c) (4) (d) (3) END OF PAPER

11 Baptist Lui Ming Choi Secondary School First Term Examination ( ) Form 3 Chemistry Suggested Answers Section A: Multiple Choice (20%) 1. A D A C C 6. B B D C A 11. D B C A B 16. C D D B A Section B: True or False (10%) Put a in the correct answer T F Section C: Matching (10%) Column I Column II B E K / A G J M A L C D Section D: Fill in the blanks (10%) 1. (a) _toxic/poisonous_ (b) irritant 2. (c) _compound (d) oxygen (e) electrolysis 3. (f) solute (g) water 4. (h) _Atmosphere_ 5. (i) carbon dioxide (j) _water/water vapour_ Section E: Structural Questions (50%) 1. (a) Oxygen is an element [1] because it is a pure substance which cannot be broken down into anything simpler by chemical methods. [1] (b) (i) Nitrogen [1] (ii) It is because it provides an inert atmosphere / it prevents unwanted reactions caused by air. [1] (c) (i) * Fractional distillation [1] (ii) It is because the gases have different boiling points. [1] (iii) It is a physical change because no new substance is formed. [2] (d) Using glowing splint. Oxygen relights the glowing splint but nitrogen does not. [1+2] (e) Oxidizing [1]

12 2. (a) Aluminium [1] (b) Any three: solid / silvery(or silvery white) colour / good conductor of electricity / good conductor of heat / malleable / ductile / high m.p. or b.p. / non-toxic / any reasonable answers [3] (c) Making window frame / body of aircraft / any reasonable answers [1] (d) (i) _aluminium/ metal W_ + oxygen _aluminium oxide / oxide of metal W [1] (ii) It is a chemical change because a new substance, aluminium oxide, is formed. [2] P.2 3. (a) (i) * Carbon dioxide [1] (ii) It is because it does not melt to become liquid / it sublimes. [1] (iii) The cube of dry ice dissolves and colourless gas bubbles are evolved. [2] (b) (i) * Sodium and chlorine [2] (ii) Making salt-fish / as a preservative. [1] (iii) Sea water [1] (iv) * Filtration and crystallization [2] 4. (a) (i) A:_Calcium B:_Potassium_ [2] (ii) Wear safety spectacles / gloves [1] (b) (i) Nitric acid [1] (ii) * Chloride ion [1] (iii) * Silver chloride [1] (iv) Calcium chloride + silver nitrate silver chloride + calcium nitrate [2] 5. (a) * Evaporation [1] (b) (i) Hydrogen gas [1] (ii) It burns with a pop sound. [2] (iii) As a rocket fuel or making ammonia/fertilizer/hydrochloric acid/margarine [1] (c) It turns moist blue litmus paper red and then white [4] (d) thermometer Sea water Anti-bumping heat Tap water/cold water [3] granules Distillate (pure water/distilled water) * : correct spelling