Baptist Lui Ming Choi Secondary School
Name: ______/ F.6 Mock Examination (2011-12) / Date: 20/2/2012Class: ______( ) / Combined Science - Chemistry / Time: 8:40–10:20a.m.
INSTRUCTIONS
1. / There are TWO sections, A and B, in this Paper. Section A carries 24 marks and Section B carries 56 marks. You are advised to finish Section A in about 30 minutes.2. / Section A consists of multiple-choice questions in this question book, while Section B contains conventional questions printed separately in Question-Answer Book B.
3. / Answers to Section A should be marked on the Multiple-choice Answer Sheet while answers to Section B should be written in the spaces provided in Question-Answer Book B. The Answer Sheet for Section A and the Question-Answer Book for Section B must be handed in separately at the end of the examination.
4. / An asterisk (*) has been put next to the question where effective communication is assessed.
5. / A Periodic Table is printed on the back of the Question-Answer Book B. Atomic numbers and relative atomic masses of elements can be obtained from the Periodic Table.
SECTION A (MULTIPLE-CHOICE QUESTIONS)
1. / In an experiment, one mole of hydrocarbon reacts completely with one mole of hydrogen gas in the presence of a heated catalyst. Which of the following may be the formula of the hydrocarbon?A. C5H10 B. C5H11OH C. C5H12 D. C9H20
2. / Which of the following statements about ethanol is correct?
A. It changes orange acidified potassium dichromate solution to green.
B. It reacts with sodium carbonate solution to give carbon dioxide.
C. There is effervescence when a piece of magnesium ribbon is put in it.
D. It turns blue litmus paper red.
3. / Which of the following is NOT a covalent substance?
A. NH3 B. NH4Cl C. I2 D. SiO2
P.T.O.
Form 6 / Combined Science - Chemistry / P.24. / Given 28.6 g of ethyl ethanoate are obtained from 23 g of ethanol during the esterification with ethanoic acid. What is the percentage yield of the ester in the reaction?
A. 81.56% B. 75% C. 65% D. 54.79%
5. / Consider the following compounds:
Compound X / Compound Y
Which of the following statements about the above two compounds is correct?
A. Both compounds have the same boiling point.
B. Both compounds can turn pH paper to red.
C. Both compounds have the same molecular formula.
D. Both compounds have the same odour.
6. / Chlorine has a relative atomic mass of 35.5 and has two isotopes with relative isotopic masses of 35 and 37. Which of the following statements about chlorine are CORRECT?
(1) The isotopes have same atomic number.
(2) It contains the two isotopes, chlorine-35 and chlorine-37, in a ratio of 1:3.
(3) The two isotopes have same reactivity.
A. (1) and (2) only B.(1) and (3) only C.(2) and (3) only D.(1), (2) and (3)
7. / The chloride of a metal X has the formula XCl3 and contains 65.6% by mass of chloride. Find the relative atomic mass of X.
A. 27.0 B. 55.8 C. 69.7 D. 203
8. / When 10.6 g of anhydrous sodium carbonate was added to 200.0 cm3 of 1.0 M sulphuric acid at room conditions, the reaction stopped in 40 seconds. At the same time, 2400 cm3 of carbon dioxide was produced. Which of the following statements about the reaction is INCORRECT?
A. The average rate of decrease in mass of sodium carbonate was 15.9 g min-1
B. The average rate of decrease in concentration of the acid was 0.0125 mol dm-3 s-1
C. The average rate of increase in volume of carbon dioxide was 60 cm3 s-1
D. Sodium carbonate and sulphuric acid just reacted completely.
To be continued
Form 6 / Combined Science - Chemistry / P.39. / After the addition of marble chips to an excess of dilute hydrochloric acid in a conical flask, each of the following was measured and plotted against time on a graph.
/
If the reaction was complete in 2.5 minutes, which of the following, when plotted against time, would give a graph like the one shown above?
A. Total mass of the conical flask and its contents
B. Volume of carbon dioxide produced
C. pH of the solution
D. Temperature of the solution
10. / Which of the following equations represents a reaction which is impossible to take place?
A. Cu(OH)2 + H2SO4 ® CuSO4 + 2H2O
B. CuO + 2HNO3 ® Cu(NO3)2 + H2O
C. Cu + 2HCl ® CuCl2 + H2
D. CuCO3 + 2CH3COOH ® (CH3COO)2Cu + H2O + CO2
11. / Gas U is bubbled into a solution of V as shown in the diagram. There is a reaction between U and the solution of V. Which of the following combinations about U and V is correct? /
U
/V
A. / Sulphur dioxide / Sodium hydroxideB. / Oxygen / Sodium hydroxide
C. / Chlorine / Potassium sulphate
D. / Hydrogen / Sodium iodide
P.T.O.
Form 6 / Combined Science - Chemistry / P.412. / Solution A is an aqueous solution with pH 3 while solution B is an aqueous solution with pH 1. How does the [H+(aq)] in solution A compare with that in solution B?
A. The [H+(aq)] in solution A is three times greater than the [H+(aq)] in solution B.
B. The [H+(aq)] in solution A is one third of the [H+(aq)] in solution B.
C. The [H+(aq)] in solution A is of the [H+(aq)] in solution B.
D. The [H+(aq)] in solution A is of the [H+(aq)] in solution B.
13. / Which of the following reagents can decolourize acidified potassium permanganate solution?
(1) Na2SO3(aq) / (2) Fe(NO3)3(aq) / (3) KI(aq)
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
14. / Which of the following underlined species have an oxidation number of +2?
(1) PbO (2) Mg (3) [CuCl4]2-
A. (1) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
15. / A white solid dissolves in water to form an acidic solution. The solution reacts with aqueous sodium hydroxide on heating to give a gas. The solid is probably
A. calcium oxide. B. sodium carbonate.
C. ammonium chloride. D. sodium chloride.
To be continued
Form 6 / Combined Science - Chemistry / P.516. / Which of the following statements is/are CORRECT when zinc nitrate solution is added to iron(II) sulphate solution?
(1) Colour of iron(II) sulphate solution becomes paler.
(2) White precipitate is given out.
(3) Zinc displaces iron since zinc is more reactive than iron.
A. (1) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
17. / Given that:
P4(white) + 5O2(g) ® P4O10(s) / ΔH 1 = -2983.2 kJ mol-1
Which of the following statements concerning the conversion of white phosphorus to red phosphorus is/are correct?
(1) The reaction is exothermic.
(2) Temperature of the surroundings decreases.
(3) The enthalpy of red phosphorus is relatively higher than that of white phosphorus.
A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only
18. / Which of the following equations represents the standard enthalpy change of formation of hydrogen bromide?
A. H2(g) + Br2(g) ® 2HBr(g)
B. H2(g) + Br2(l) ® 2HBr(g)
C. H2(g) + Br2(g) ® HBr(g)
D. H2(g) + Br2(l) ® HBr(g)
P.T.O.
Form 6 / Combined Science - Chemistry / P.619. / Which of the following statements concerning urea-methanal is correct?
A. It is a thermosetting plastic.
B. It melts in boiling water.
C. It is usually used instead of glass.
D. It is an addition polymer.
20. / Which of the following statements concerning the electrolysis of sodium nitrate solution using graphite electrodes are CORRECT?
(1) Na+(aq) ions are preferentially discharged at the cathode to form Na(s).
(2) OH-(aq) ions are preferentially discharged at the anode to form O2(g).
(3) The concentration of the sodium nitrate solution remains unchanged after electrolysis.
A. (1) only
B. (2) only
C. (1) and (2) only
D. (2) and (3) only
21. / Which of the following equations represents a practicable way of preparing the salt underlined?
A. Mg(OH)2 + Na2SO4 ® MgSO4 + 2NaOH
B. NH3 + HNO3 ® NH4NO3
C. Cu + H2SO4 ® CuSO4 + H2
D. AgCl + NaNO3 ® NaCl + AgNO3
22. / Rubidium(Rb) and indium(In) are both metals in Period 5. Which of the following statements concerning rubidium and indium are CORRECT?
(1) Indium reacts with chlorine gas more readily than rubidium.
(2) They are very good conductors of heat.
(3) They both have five occupied electron shells.
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
To be continued
Form 6 / Combined Science - Chemistry / P.7Directions: / Each question below (Questions 23 to 24) consists of two separate statements. Decide whether each of the two statements is true or false; if both are true, then decide whether or not the second statement is a correct explanation of the first statement. Then select one option from A to D according to the following table:
A. / Both statements are true and the second statement is a correct explanation of the first statement.
B. / Both statements are true and the second statement is NOT a correct explanation of the first statement.
C. / The first statement is false but the second statement is true.
D. / Both statements are false.
First Statement / Second Statement
23. / Sulphur does not conduct electricity. / Sulphur is a solid at room conditions.
24. / No energy is absorbed or released in a physical change. / Physical changes do not involve breaking of bonds.
END OF SECTION A
Baptist Lui Ming Choi Secondary School
Name: ______/ F.6 Mock Examination (2011-12) / Marks:______Class: ______( ) / Combined Science - Chemistry / Time: 8:40–10:20a.m.
SECTION B (QUESTION-ANSWER BOOK)
Answer ALL questions. Write your answers in the spaces provided.
1. / (a) / A sodium hydroxide solution has been exposed to air for a long time. When dilute hydrochloric acid is added to it, colourless gas bubbles are given out. Explain the observation with the help of equations.(4 marks)
(b) / Suggest a chemical test to distinguish each of the following pairs of solutions. Each test should include the reagent(s), the expected observation with each compound and the chemical equation(s)
(i) / Sodium chloride solution and sodium iodide solution.
(ii) / Magnesium nitrate solution and ammonium nitrate solution.
(6 marks)
P.T.O.
Form 6 / Combined Science - Chemistry / P.22. / (a) / Scientists believe that liquid hydrogen could be a substitute for fossil fuel in future.
(i) / Liquid hydrogen is used as a fuel in space shuttles now. Explain why liquid, but not gas, is used.
(ii) / Suggest a method to obtain hydrogen from sea water.
(2 marks)
(b) / The following diagram shows a hydrogen-oxygen fuel cell.
(i) / Point out TWO mistakes in the diagram and correct them.
(ii) / Suggest a metal for making the electrodes of the fuel cell.
(3 marks)
To be continued
Form 6 / Combined Science - Chemistry / P.33. / Polystyrene can be produced by the set-up shown below.
(a) / State the function of kerosene in this experiment.
(b) / State the function of apparatus A.
(c) / Write a chemical equation for the formation of polystyrene.
(d) / Explain whether polystyrene is suitable for making electrical sockets.
(4 marks)
P.T.O.
Form 6 / Combined Science - Chemistry / P.44. / Compound P has 60% of carbon, 13.33% of hydrogen and 26.67% of oxygen by mass. P can be converted to an alkanoic acid Q with the same number of carbon atoms. Q can be converted to a salt R by reacting with sodium hydroxide. P reacts with Q to give compound S which has a pleasant smell.
(a) / If the molecular mass of P is 60, what is its molecular formula?
(b) / Give the IUPAC name of Q.
(c) / What are the reagents and conditions for the conversion of P to Q?
(d) / Write a chemical equation for the formation of R.
(e) / Give the IUPAC name of S.
(f) / Suggest one daily use of S.
(8 marks)
To be continued
Form 6 / Combined Science - Chemistry / P.55. / In an experiment to determine the concentration of ammonia solution, 25.00 cm3 of the ammonia solution was transferred into a conical flask and titrated against 0.1 M sulphuric acid. A few drops of indicator were added. The titration results are listed in the table below:
1 / 2 / 3 / 4
Final reading (cm3) / 15.90 / 16.70 / 18.40 / 18.50
Initial reading (cm3) / 0.00 / 1.50 / 3.10 / 3.40
(a) / Which indicator is suitable for this titration?
(b) / What would be the colour change of the indicator at the end point?
(c) / Write a chemical equation for the reaction between ammonia solution and sulphuric acid.
(d) / (i) / Calculate the reasonable average volume of sulphuric acid used.
(ii) / Calculate the molarity of ammonia solution.
(7 marks)
P.T.O.