Candidate Name: Class Registration No NATIONAL JUNIOR COLLEGE SH1 CHEMISTRY PROMOTIONAL EXAMINATION H2 CHEMISTRY PAPER 2 6 October 2009 Multiple Choice TIME: 45 minutes INSTRUCTIONS TO CANDIDATES Do not open this booklet until you are told to do so.
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Candidate Name:
Class Registration No
NATIONAL JUNIOR COLLEGESH1 CHEMISTRY PROMOTIONAL EXAMINATION
H2 CHEMISTRY PAPER 2 6 October 2009 Multiple Choice
TIME: 45 minutes
INSTRUCTIONS TO CANDIDATES
Do not open this booklet until you are told to do so.Write your name, class and registration number in the spaces provided at the top of this page as well as on the optical mark sheet provided.
Shade the index number in a 5 digit format (12345) on the optical mark sheet.Row 1: Year of admission
9 for JC1 7 for IP Row 2: Level on admission
5 for JC1 3 for IP
Rows 3, 4 and 5: Last 3 digits of registration number
Eg: Reg No 0905648 = 95648 Reg No 0703093 = 73093
There are 25 questions in this paper. Answer ALL questions.
For each question, there are four possible answers, A, B, C and D. Choose the one you consider correct and record your choice in 2B pencil in the optical mark sheet.
Submit both the optical mark sheet as well as the question paper at the end of the examination.
Section A
For each question in this section, there are four possible answers, A, B, C and D. Choose the one you consider to be correct.
1 Which one of the species is deflected to the least extent in an electric field?
A Mg2+
B Al3+
C O2-
D P3
2 An element Y can exist in a few oxidation states. 12.50 cm3 of an aqueous solution of 0.800 mol dm3 of Y2+ ions needed 40.00 cm3 of 0.100 mol dm3
acidified KMnO4 (aq) for complete reaction. What is the final oxidation state of Y?
A +4
B +3
C 0
D -1
3 In which one of the following reactions does the underlined species undergo oxidation?
A Ca + F2 → CaF2
B 2 Bi + 3 SnO32 + 3 H2O → 2 Bi(OH)3 + 3 SnO2
2−
C 2 H2S + SO2 → 2 H2O + 3 S
D 2 NCl3 + 6 NaOH → N2 + 3 NaCl + 3 NaOCl + 3 H2O
4 The shapes of the following species :
F2O, PH4+, ICl4−, I3
− are
A linear, tetrahedral, square pyramid and trigonal planar respectively
B bent, tetrahedral, square planar and linear respectively.
C linear, trigonal pyramidal, tetrahedral and bent respectively.
D bent, trigonal bipyramidal, tetrahedral and linear respectively.
2
This question paper consists of 10 printed pages (including this page)
5 In which one of the following pairs of compounds is the first member less volatile than the second?
A CO2 CS2
B PH3 NH3
C
D CaO MgO
6 Trimethyoprim (TMP) is used for the treatment and prevention of urinary tract infection. It has the following structure:
In which sequence is the bond angles quoted in decreasing order?
A x > y > w > z
B x > y > z > w
C y > z > w > x
D y > w > z > x
7 Flask C contains 1.5 dm3 of nitrogen at 3 kPa pressure and flask D contains 2.5 dm3 of argon at 1 kPa pressure.
If the flasks are connected at constant temperature, what is the final pressure in the system?
A
B
C 2
D 4
3
y
wx z
8 P and Q are ideal gases which occupy containers A and B respectively at 298K. The volume of container A is half that of container B, but the mass of 1 mol of P is four times that of Q.
For a same given mass of P and Q, what is the ratio of the gas pressures in container A to container B?
A 0.5
B 1
C 2
D 4
9 10 dm3 of ethene were burnt in 40 dm3 of oxygen gas and the resulting mixture cooled to room temperature. The residual gas would contain
A equal volume of carbon dioxide and water.
B twice the volume of water as oxygen.
C twice the volume of oxygen as carbon dioxide.
D twice the volume of carbon dioxide as oxygen.
10 Nitrogen dioxide, NO2, decomposes on heating according to the following equation.
2 NO2(g) 2 NO (g) + O2(g)
When 1 mol of nitrogen dioxide were placed into a 1 dm3 container and heated, 60% of NO2 had dissociated. What is the numerical value of the equilibrium constant Kc, at the temperature of the experiment?
A 0.338
B 0.675
C 1.125
D 1.481
4
Container A Container B
11 Given First and second ionization energies of calcium = + 1740 kJ mol−1
Lattice energy of calcium chloride = −2237 kJ mol−1
Enthalpy of hydration of calcium ion = −1650 kJ mol−1
Enthalpy of solution of calcium chloride = − 348 kJ mol−1
Electron affinity of chlorine = − 141 kJ mol−1
The enthalpy of hydration of chloride ion is
A − 78 kJ mol−1
B −468 kJ mol−1
C −728 kJ mol−1
D −935 kJ mol−1
12 The standard enthalpy of formation, ∆Hof for O3(g) is +142 kJ mol−1.
Which one of the following statements involving ozone is INCORRECT?
A Decreasing the temperature will increase the amount of O2 gas in an equilibrium mixture containing only O2(g) and O3(g).
B Decreasing the pressure will increase the amount of O2 gas in an equilibrium mixture containing only O2(g) and O3(g).
C O3 is energetically less stable than oxygen.
D The activation energy for converting O3 to O2 is higher than that for O2 to O3.
13 When 25 cm3 of 0.5 mol dm−3 hydrochloric acid is reacted with an equal volume of 0.5 mol dm−3 potassium hydroxide, the temperature of the mixture rose by3.4 oC.
What will be the temperature change if 50 cm3 of 1 mol dm−3 hydrochloric acid is mixed with an equal volume of 1 mol dm−3 potassium hydroxide?
A 1.7
B 3.4
C 6.8
D 13.6
5
14 A 1 mol sample of ethanoic acid is diluted at constant temperature to a volume V.
Which diagram shows how Ka, the acid dissociation constant varies with V?
A B
C D
15 A 1.0 x 10–3 mol dm–3 aqueous solution of a weak, monobasic acid HA has a pH
of 4.0.
What is the approximate pKa value for the acid?
A 5.0
B 6.0
C 7.0
D 8.0
16 A first-order reaction is 50% complete at the end of 30 minutes. In how many minutes is the reaction 75% complete?
A 15 minutes
B 30 minutes
C 45 minutes
D 60 minutes
6
Ka
V
Ka
V
Ka
V
Ka
V
17 The mechanism for the reaction between nitric oxide and oxygen is an important intermediate step in the production of nitric acid. It was suggested that the mechanism involves the following two steps:
2NO → N2O2 fastN2O2 + O2 → 2NO2 slow
Which diagram represents the reaction profile for this mechanism?
A B
C D
18 When an acidic solution containing 0.10 mol dm−3 of zinc sulfate and 0.10 mol dm−3 of copper(II) sulfate is saturated with hydrogen sulfide (at 15°C), the concentration of S2−(aq) in the solution is found to be 10−41 mol dm−3. [At 15°C, Ksp(ZnS) = 10−24 mol2 dm−6; Ksp(CuS) = 10−40 mol2 dm−6.]
Which one of the following describes what happens in the solution?
A No precipitate is formed.
B Copper(II) sulfide only is precipitated.
C Copper(II) sulfide is precipitated followed by zinc sulfide.
D Zinc sulfide is precipitated followed by copper(II) sulfide.
7
Energy
Reaction path
Energy
Reaction path
Energy
Reaction path
Energy
Reaction path
Section B
For each of the questions in this section one or more of the three numbered statements 1 to 3 may be correct.
Decide whether each of the statements is or is not correct (you may find it helpful to put a tick against the statements which you consider to be correct).
The responses A to D should be selected on the basis of
A B C D
1, 2 and 3 are correct
1 and 2 only are correct
2 and 3 only are correct
1 only is correct
No other combination of statements is used as a correct response.
19 Which of the following statements are INCORRECT?
1 One mole of hydrogen gas contains 6.02 x 1023 atoms of hydrogen.
2 One mole of Ne ions is formed by removing 6.02 x 1023 electrons from a mole of Ne atoms.
3The mass of one molecule of water is
20 Consider the species in the following equation:
[Ti(H2O)4Cl2]+(aq) + 2H2O(l) [Ti(H2O)6]3+(aq) + 2Cl−(aq)
Correct statements include
1 Titanium has undergone a change in oxidation state.
2 The complex ions are both octahedral.
3 The aqueous [Ti(H2O)6]3+ ions react with sodium carbonate to give carbon dioxide gas.
8
21Particles Number of neutrons Number of nucleons
Q− 16 33
R 19 39
S2− 17 33
T2 18 35
Which of the following pairs consists of isoelectronic particles?
1 Q− and S2−
2 R and T2
3 S2− and T2
22 The decomposition of X is given as 3X → 2Y + Z.A straight line through the origin is obtained when the rate of decomposition is plotted against the square of the concentration of X. From the given information alone, it can be deduced that
1 it is a second order reaction.
2 the reaction must take place in stages.
3 the rate of the decomposition will be increased by increasing temperature.
23 Which of the followings particles would, on losing an electron, have a half-filled p - subshell?
1 P+
2 O
3 N−
A B C D
1, 2 and 3 are correct
1 and 2 only are correct
2 and 3 only are correct
1 only is correct
9
24 Two gases have the same density under the same conditions of temperature and pressure. Which statements about these two gases must be correct?
1 They have the same relative molecular mass.
2 There are equal numbers of moles of gas in the two samples.
3 They condense at the same temperature.
25 Which graphs show the correct trend for the physical property stated?
1
2
3
Ans
A B C D
1, 2 and 3 are correct
1 and 2 only are correct
2 and 3 only are correct
1 only is correct
10
Cl22 Br2
2
I2
Boiling point of halogens
HCl HBr HI
Boiling point of hydrogen halides
HCl HBr HI
Bond length in HX
1 A A D B C6 D B A D B11 B D C D A16 D C A D C21 D B C D D
11
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