FIJI SEVENTH FORM CERTIFICATE EXAMINATION 2011
CHEMISTRY PAPER 1
Time Allowed: Three Hours
(An extra ten minutes is allowed for reading this paper.)
INSTRUCTIONS
1. Write all your answers in the Answer Book provided.
2. Write your Index Number on the front page and inside the back flap of the Answer Book.
3. If you require more paper, ask the supervisor for extra sheets. Tie these inside the Answer Book at the appropriate places.
4. You may use a calculator, provided it is silent, battery-operated and non-programmable.
In Sections B and C, working should be shown in the questions involving calculations.
5. There are three sections in this paper. All the sections are compulsory.
Note : A Periodic Table of Elements is provided for your use during this examination. Both the atomic number and the relative atomic mass for each element are given.
SUMMARY OF QUESTIONS
Section Guidelines Total
Mark
Suggested Time
A
There are twenty-four multiple-choice questions.
All the questions are compulsory.
24 43 minutes
B There are twelve questions.
All the questions are compulsory.
36 65 minutes
C There are five questions.
All the questions are compulsory.
40 72 minutes
2.
SECTION A
[24 marks]The multiple-choice questions in this section are all compulsory. Each question is worth 1 mark.
INSTRUCTIONS FOR MULTIPLE – CHOICE QUESTIONS
1. In your Answer Book, circle the letter which represents the best answer. If you change your mind, put a line through your first choice and circle the letter of your next choice.
For example:
2. If you change your mind again and like your first answer better, put a line through your second circle and tick () your first answer.
For example:
3. No mark will be given if you circle more than one letter for a question.
1. How many different orbitals are there in the 3s, 3p and 3d subshells respectively?
A. 1, 3, 5 B. 1, 4, 9 C. 2, 6, 10 D. 2, 8, 18
2. The atoms X and Y have the following electron configuration:
X – 1s2 2s2 2p6 3s2 3p6 3d10 4s2 Y – 1s2 2s2 2p4
Which of the following correctly represents the formula obtained when X and Y are allowed to react?
A. XY B. XY2
C. XY4
D. X2Y4
© MINISTRY OF EDUCATION, FSFCE 2011: CHEMISTRY.
12 A B C D
12 A B C D
3. In which of the following processes will hydrogen bonds break?
A. H2(l) H2(g)
B. NH3(l) NH3(g)
C. 2HI(g) H2(g) + I2(g)
D. CH4(g) C(g) + 4H(g)
4. In a molecule of ethene, C2H4, how many pi bonds are present?
A. 1 B. 2 C. 3 D. 4
5. Hydrogen and oxygen gases react according to the following equation:
2H2(g) + O2(g) 2H2O(g)
If all volumes are measured at 110 °C and 1 atmospheric pressure, the volume of steam produced after 50 cm3 of hydrogen reacts completely with 25 cm3 of oxygen is
A. 25 cm3 B. 50 cm3 C. 75 cm3 D. 100 cm3
6. A flexible balloon containing 3 L of hydrogen gas at 27 °C and 101 kPa was allowed to ascend through the atmosphere. At some height in the stratosphere when the pressure was 2.1 kPa and the temperature was 2 °C, the volume of the gas in the balloon would be
4.
7. The reaction equation for the combustion of carbon is
C(s) + O2(g) CO2(g) ∆H°reaction = – 393 kJ
How many grams of C(s) must burn in this way to release 275 kJ of heat?
A. 0.70 g B. 1.43 g C. 8.40 g D. 17.10 g
8. The specific heat of iron is 0.473 J/g°C. A 400.0 g sample of iron at 20.0 °C releases 2 270.4 J of heat energy. What would be the new temperature of the iron?
A. 8.0 °C B. 12.0 °C C. 20.0 °C D. 32.0 °C
9. “Silicon tetrachloride is readily hydrolysed.” This statement means that
A. silicon tetrachloride is very soluble in water.
B. a solution of silicon tetrachloride in water is slightly acidic. C. silicon tetrachloride reacts rapidly and completely in water.
D. silicon tetrachloride reacts rapidly with boiling dilute acid solution.
10. The chloride that is most unstable at room temperature and pressure is
A. CCl4
B. PbCl4
C. SnCl4
D. SiCl4
11. The oxide and chloride of an element W are separately mixed with water. Both the resulting solutions have the same effect on litmus paper. Element W is
A. sodium. B. aluminium. C. magnesium. D. phosphorus.
12. Which of the following is not an asymmetric alkane?
A. 3 – methylhexane B. 3 – methylheptane C. 3 – methylpentane D. 4 – methyloctane
13. Which of the following compounds is an aromatic compound?
A. C2H2
B. C6H12
C. C6H4Br2
D. C2H4Br2
14. Consider the molecules:
CH3 CH2 O CH2 CH3 CH3 CH2 CH2 CH2 OH
The two molecules given above are examples of
A. geometrical isomers. B. structural isomers. C. optical isomers. D. stereoisomers.
15. Which of the following molecular formula cannot represent an ether?
A. CH4O
B. C2H6O
C. C3H8O
D. C4H10O
16. Amines are known as organic
A. acids that react with water to produce ammonia. B. bases that react with water to produce ammonia. C. acids that react with acids to form ammonium salts. D. bases that react with acids to form ammonium salts.
6.
17. When CH3 CH CH2 is reacted with water in the presence of an acid catalyst, a new
compound is formed. Which of the following would be the product of this reaction?
A. CH3 CH2 CH3
B. CH3 CH CH3
H O
C. CH3 C CH3
O
D. CH3 CH CH2 OH
H O H
18. The reaction which can be described as substitution is
A. propane + chlorine + uv light.
B. propene + hydrogen with nickel catalyst. C. 1-butanol + potassium permanganate solution. D. 1-propanol + ethanoic acid with H3O+ catalyst
19. A titration of an acid and base to the equivalence point results in a noticeably acidic solution. This titration is likely to involve a
A. weak acid and a weak base. B. strong acid and a weak base. C. weak acid and a strong base. D. strong acid and a strong base.
20. The expression for the equilibrium constant, Kc, for the reaction:
2 SO2(g) + O2(g) 2 SO3(g) is
A. ] O [ ] SO [ 2 ] SO [ 2 2 2 3 B. 2 3 2 2 2 ] SO [ ] O [ ] SO [ C. ] O [ ] SO [ ] SO [ 2 2 2 2 3 D. ] O [ ] SO [ ] SO [ 2 2 3
21. The pH of a new brand of orange juice is approximately 5.0. How many times greater is the [H3O+] in this orange juice than in underground water having a pH of 8.0?
A. 0.63 B. 1.60 C. 1 000 D. 10 000
22. What is the oxidation number of oxygen in dioxygen difluoride, O2F2?
A. - 2 B. - 1 C. + 1 D. + 2
23. Consider the half-equations given below:
V 7 . 0 E
S e
2 S
3 (l)+ − 32(aq− ) ° = −
V 7 . 2 E
Na e
Na(+l) + − (l) ° = −
The reactant at the anode and the anode’s polarity is
Reactant Polarity
A. sodium negative
B. sulphur negative
C. sulphur ions positive
D. sodium positive
24. For the electrochemical cell: Cd(s) Cd2(aq+) Sn(2aq+) Sn(s)
the E° is – 0.53 V
If these species are placed together and allowed to react, the species which would act as the reducing agent would be
A. Cd B. Cd2+ C. Sn2+ D. Sn
8.
SECTION B
[36 marks]The twelve questions in this section are all compulsory. Each question is worth 3 marks.
QUESTION 1
(a) Europium, E, exists in nature as two isotopes with the following abundance:
% 48 E
% 52 E
153 151
= =
Compute the relative atomic mass of Europium. (2 marks)
(b) Account for the fact that the melting point of magnesium is higher than that
of sodium. (1 mark)
QUESTION 2
(a) Consider the successive ionisation energies of element Z.
Element
Ionisation Energies (kJ mol–1)
1st 2nd 3rd 4th
Z 738 1 450 7 732 10 550
(i) Which group of the Periodic Table does element Z belong to? (½ mark)
(ii) Give an explanation to your answer in (i) above. (1 mark)
(b) A set of four quantum numbers for the outermost electron of a non-transition metal is given below:
4, X, 0, + ½
(i) List the possible value(s) of X. (½ mark)
(ii) Identify the type of bonding that would exist between chlorine and the
above metal. (½ mark)
(iii) Give a physical property of the compound formed between the above
metal and chlorine. (½ mark)
QUESTION 3
(a) An alcohol solution contains 142.0 g of isopropanol (C3H7OH) and 58.0 g of
water. Calculate the mole fraction of isopropanol. (1½ marks)
(b) If 4 moles of a gas at a pressure of 80.43 kPa has a volume of 120 L, what is
its temperature? [R = 8.314 Jmol-1K-1] (1½ marks)
QUESTION 4
(a) Define the term transition metal. (1 mark)
(b) Transition elements are characterised by the following features:
1. variable oxidation states 2. coloured compounds
With reference to chromium illustrate the above features. (2 marks)
QUESTION 5
(a) Explain why NH3 readily forms complexes with many transition metal ions
while NH does not. +4 (1 mark)
(b) By comparing the first ten transition metals, comment on why Cr and Cu both have only one electron in the 4s orbital while the other transition metals have
two electrons. (1 mark)
(c) In order to predict whether a molecule will be polar or non-polar we have to
consider two things. Describe these two considerations. (1 mark)
10.
SECTION B (continued)
QUESTION 6
Calculate H∆ for the reaction: 2Ga(s) + 3H2(g) Ga2H6(g) given the following reactions: 1 ) s ( 3 2 ) g ( 2 ) s
( O Ga O H 1188kJmol
2 3 Ga
2 + ∆ = − −
1 ) ( 2 ) s ( 3 2 ) g ( 2 ) g ( 6
2H 3O Ga O 3H O H 2158kJmol
Ga + + l ∆ = − −
1 ) g ( 2 ) g ( 2 ) g (
2 O H O H 242kJmol
2 1
H + ∆ = − −
1 ) g ( 2 ) (
2O H O H 44kJmol
H l ∆ = + −
(3 marks)
QUESTION 7
(a) Give the systematic name of the organic compound given below.
(1 mark)
(b) Select the correct formula (1 – 5) from the list given below to answer the questions which follow.
1. C3H7CHCH2 4. C2H5COOC2H5
2. CH3CH2CH3 5. C4H9COCl
3. C3H7CHOHCH3
(i) Which has the empirical formula CH2? (½ mark)
(ii) Which decolourises aqueous bromine? (½ mark)
(iii) Which reacts with aqueous NaOH to produce an alcohol as one of the
two organic products? (½ mark)
(iv) Which reacts readily with aqueous NH3 to produce an amide? (½ mark)
© MINISTRY OF EDUCATION, FSFCE 2011: CHEMISTRY. CH3 CH2
C C
H
CH3
CH CH3
QUESTION 8
Give only the structural formula of the major organic product of the following transformations.
(a) + Br2 (1 mark)
(b) CH3 CH2 CH CH CH3 (1 mark)
OH CH3
(c) CH3CH C(CH3)CH2CH3 + HBr (1 mark)
QUESTION 9
(a) Draw the geometric isomers of 2-butene. (1 mark)
(b) Classify the following alkyl halides as primary, secondary or tertiary.
(i) (CH3CH2)3C Cl
(ii) Br CH2CH2 Br (1 mark)
(c) CH3COCl can be used as the starting material for the synthesis of a number of
carboxylic acid derivatives.
Give the reaction reagent(s) that would be needed for each of the following transformations.
(i) CH3COCl CH3COOCH2CH3 (½ mark)
(ii) CH3COCl CH3COOH (½ mark)
QUESTION 10
40 cm3 of 0.8 mol L-1 barium chloride and 60 cm3 of 0.5 mol L-1 sodium hydroxide solutions are added together. Calculate whether any precipitate of barium hydroxide
will form. [Ksp(BaOH)2 = 5.0 x 10-3] (3 marks)
Turn Over © MINISTRY OF EDUCATION, FSFCE 2011: CHEMISTRY.
FeBr3
12.
SECTION B (continued)
QUESTION 11
The following questions are based on the unbalanced equation:
) g ( 2 )
aq ( 3 )
aq ( 3 )
s (
2 NO IO NO
I + − − +
(a) Write the balanced reduction half equation. (1 mark)
(b) Write the balanced oxidation half equation. (1 mark)
(c) Give the overall balanced equation in an acidic medium. (1 mark)
QUESTION 12
(a) How much sodium hydroxide (NaOH) in grams is needed to prepare 546 cm3
of solution with a pH of 10.0? [M(NaOH) = 44 g mol-1] (2 marks)
(b) Consider the electrochemical reaction:
V 84 . 0 E
Cl Sn
AuCl
Sn2(aq+) + −4(aq) (4aq+) + −(aq) ocell = +
Given that the standard electrode potential for the Sn4+/Sn2+electrode system
is + 0.14 V, calculate the standard electrode potential for the AuCl4− / Au
system. (1 mark)
SECTION C
[40 marks] The five questions in this section are all compulsory.Each question is worth 8 marks.
QUESTION 1
(a) Name the elements with the following electron configuration:
(i) [Ne] 3s2 3p4 (½ mark)
(ii) [Ar] 4s2 (½ mark)
(b) (i) Draw the Lewis structure of NO 3− (1 mark)
(ii) Explain the shape of NO using VSEPR theory. −3 (1 mark)
(c) (i) Based on the postulates of the kinetic molecular theory, give the conditions of pressure and temperature that would cause a real gas to
best resemble an ideal gas. (1 mark)
(ii) Using one of the conditions mentioned in part (i) above, explain your
answer. (1 mark)
(d) Explain briefly the thermal stability trend of the monoxides and dioxides of
Group IV elements. (2 marks)
(e) A balloon contains 0.1 moles of oxygen and 0.4 moles of nitrogen. If the balloon
is at standard temperature and pressure, what is the partial pressure of nitrogen? (1 mark)
QUESTION 2
(a) (i) Name the complex ion
[
Fe(H2O)6]
3+ (1 mark)(ii) Define the term co-ordination number with reference to
[
Fe(H2O)6]
3+ (1 mark)(iii) Give the formula of the complex ion tetrachlorocuprate (II) ion. (1 mark)
14.
SECTION C (continued)
(b) Consider the Period II elements of the periodic table and give the:
(i) name the element that when reacted with fluorine will have the greatest
ionic character. (½ mark)
(ii) formula of a simple molecule that has pure covalent bonding. (½ mark)
(iii) name of the element that has the greatest metallic character. (½ mark)
(c) Using one example, explain what is meant by catenation. (1½ marks)
(d) A seventh former reacts 2.0 g of ammonia with 4.0 g of oxygen according to the following equation:
) g ( 2 )
g ( )
g ( 2 )
g (
3 5O 4NO 6H O
NH
4 + +
Identify the limiting reagent. (Show all necessary working). (2 marks)
QUESTION 3
(a) The production of ammonia from nitrogen and hydrogen gases can be represented by the following equation:
1 )
g ( 3 )
g ( 2 )
g (
2 3H 2NH H 92.0kJmol
N + ∆ °=− −
Calculate the bond dissociation enthalpy of the N – H bond using the bond enthalpy data given below and the equation for the production of ammonia.
Bond Bond enthalpy (kJ mol-1)
H H 436
N N 945
(2 marks)
(b) Explain why bond dissociation enthalpies are endothermic. (1 mark)
(c) The labels on three bottles have become detached. All three contain colourless liquids and are known to be aminoethane, cyclohexane and ethanol. You are supplied with red litmus papers and water. Devise a plan which would allow
you to test and identify the three liquids. (3 marks)
(d) Palm oil contains triglyceride; the structure of which is shown below. It is formed when glycerol (an alcohol) and palmitic acid (a carboxylic acid) are reacted together.
Use the structure given above to deduce the formulae of glycerol and palmitic
acid. (2 marks)
QUESTION 4
(a) The pH of a bicarbonate – carbonic acid buffer is 8.00. Calculate the ratio of the
concentration of carbonic acid (H2CO3) to that of the bicarbonate ion (HCO3−).
] 10 x 2 . 4 ) CO H ( K
[ a 2 3 = −7 (3 marks)
(b) A buffer solution is made up of approximately equal amounts of ammonium chloride and ammonia in aqueous solution.
(i) Write an equation for the reaction between ammonium ions and water. (1 mark)
(ii) Write the equation for the reaction which occurs when a small volume
of dilute hydrochloric acid is added to the buffer solution. (1 mark)
(c) Explain whether CaCl2 solution is acidic, basic or near neutral. (1 mark)
(d) Explain with relevant calculations whether the following reaction will occur.
) s ( ) s ( 2 2
) aq ( ) aq
( Pt I Pt
I
2 − + + +
Eo : I2 / I – = + 0.54 V
Pt2+/ Pt = + 1.20 V (2 marks)
Turn Over © MINISTRY OF EDUCATION, FSFCE 2011: CHEMISTRY.
CH2 O C (CH2)14 CH3
O
CH2 O C (CH2)14 CH3
O
CH O C (CH2)14 CH3
16.
SECTION C (continued)
QUESTION 5
(a) The following flow chart diagram shows the various reactions that can take place under suitable conditions using l-propanol, C3H7OH.
(i) Name the compounds A, B, C, D and E. (2½ marks)
(ii) Write the structural formula of compound E. (½ mark)
(iii) Identify the Reagents F and G. (1 mark)
(iv) Write the equations for Reaction I and Reaction II. (2 marks)
(b) Determine the reaction type in each of the following reactions:
(i) CH3CHO + NH3 CH3CH = NH (1 mark)
(ii) CH3CH2Cl + NH3 CH3CH2NH2 (1 mark)
THE END
______________________________________
COPYRIGHT: MINISTRY OF EDUCATION, REPUBLIC OF THE FIJI ISLANDS, 2011.
C3H7OH C3H6 C3H8O
C3H8 B
A
[Intermediate]
C D
E
K2Cr2O7 H2SO4 Reaction I Reagent G
K2Cr2O7
H2SO4
Reagent F
H2SO4
H2SO4 K2Cr2O7
Br2
Reaction II
HBr
