Chemistry
Standard Level
Paper 1
Grade 12 IB Mock Examination
Friday 12 January 2024
NAME:
45 mins
Instructions to candidates
● Do not open this examination paper until instructed to do so.
● Answer all the questions.
● For each question, choose the answer you consider to be the best and indicate
your choice on the answer sheet provided.
● The periodic table is provided for reference on page 2 of this examination paper.
● The maximum mark for this examination paper is [30 marks].
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12 pages
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1.
What is the sum of the coefficients when the equation is balanced with whole numbers?
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__Sn(OH)4 (aq) + __NaOH (aq) → __Na2SnO3 (aq) + __H2O (l)
A. 4
B. 5
C. 6
D. 7
2.
Methane (boiling point (− 161 oC) and tetrafluoromethane (boiling point − 128 oC) are both
greenhouse gases. The C−H bond enthalpy is 414 kJ mol−1 and the C−F bond enthalpy is 492 kJ
mol−1.
Which statements about methane and tetrafluoromethane are correct?
I. The molecules of both methane and tetrafluoromethane have a tetrahedral structure.
II. Methane is more reactive chemically than tetrafluoromethane.
III. Tetrafluoromethane is considerably more polar than methane.
A. I, II and III
B. I and II only
C. I and III only
D. II and III only
3. 0.2 mol of sodium hydrogen carbonate is decomposed by heating until constant mass.
2 NaHCO3 (s) → Na2CO3 (s) + H2O (g) + CO2 (g)
How many moles of gas are produced?
A. 0.1
B. 0.2
C. 0.3
D. 0.4
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4.
What is the degree of unsaturation (index of hydrogen deficiency) for the molecule?
A. 1
B. 2
C. 4
D. 5
5.
Naturally occurring gallium consists of the isotopes 71Ga and 69Ga. What is the approximate
percentage abundance of 69Ga?
Mr (Ga) = 69.72.
A. 40 %
B. 50 %
C. 60 %
D. 75 %
6.
What is the enthalpy change of the reaction, in kJ?
2C (graphite) + O2 (g) → 2CO (g)
A. −394 − 283
B. 2(−394) + 2(283)
C. −394 + 283
D. 2(−394) + 2(-283)
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7.
Which describes an atom of bismuth, Bi (Z = 83)?
C
8.
Which is the species oxidized and the oxidizing agent in the reaction?
MnO2 (s) + 4HCl (aq) → MnCl2 (aq) + Cl2 (g) + 2H2O (l)
D
9.
Which is correct when the ionic or atomic radii are compared?
A. Ca2+ < Ca+
B. Cl- < Cl
C. Na < Na+
D. B < C
10.
Kc is the equilibrium constant for the reaction between hydrogen and iodine:
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H2(g) + I2(g) ⇌ 2HI(g) ∆H = – 10.4 kJ
What will be the value of the equilibrium constant for the reverse reaction?
A. Kc
B. Kc½
C. Kc-1
D. Kc2
11.
What is the structure and bonding in SiO2 (s)?
A
12.
How many atoms of nitrogen are there in 0.50 mol of (NH4)2CO3?
A. 1
B. 2
C. 3.01 × 1023
D. 6.02 × 1023
13.
Which series shows the correct order of metallic bond strength from strongest to weakest?
A. 𝑁𝑎 > 𝐾 > 𝑅𝑏 > 𝑀𝑔
B. 𝑀𝑔 > 𝑁𝑎 > 𝐾 > 𝑅𝑏
C. 𝑅𝑏 > 𝐾 > 𝑁𝑎 > 𝑀𝑔
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D. 𝑀𝑔 > 𝑅𝑏 > 𝐾 > 𝑁𝑎
14.
Two 100 cm3 aqueous solutions, one containing 0.010 mol NaOH and the other 0.010 mol HCl,
are at the same temperature.
When the two solutions are mixed the temperature rises by y °C.
Assume the density of the final solution is 1.00 g cm−3.
Specific heat capacity of water = 4.18 J g−1 K−1
What is the enthalpy change of neutralization in kJ mol−1?
A.
200×4.18×𝑦
1000×0.020
B.
200×4.18×𝑦
1000×0.010
C.
100×4.18×𝑦
1000×0.010
D.
200×4.18×(𝑦+273)
1000×0.010
15. What is the maximum number of electrons that can occupy the 4th main energy level in an
atom?
A. 8
B. 14
C. 18
D. 32
16.
What is the 𝐻 − 𝐻 bond enthalpy, in 𝑘𝐽 𝑚𝑜𝑙 −1, in the 𝐻2 molecule?
2𝐻2 (𝑔) + 𝑂2 (𝑔) → 2𝐻2 𝑂(𝑔)
𝛥𝐻𝑓 (𝐻2 𝑂) = 𝑥 𝑘𝐽 𝑚𝑜𝑙 −1
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A. 𝑥 − 𝑦 + 4𝑧
B.
1
(𝑥
2
− 𝑦 + 4𝑧)
C. 𝑥 − 𝑦 + 2𝑧
D.
1
(𝑥
2
− 𝑦 + 2𝑧)
17.
Which change increases the rate of formation of hydrogen when zinc reacts with excess
hydrochloric acid, assuming all other conditions remain the same?
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
18.
A.
Adding water to the hydrochloric acid
B.
Decreasing the temperature
C.
Increasing the volume of hydrochloric acid
D.
Decreasing the size of the zinc particles while keeping the total mass of zinc the same
At equilibrium, the concentrations of chlorine and iodine are both 0.02 mol dm–3.
1
Cl2 (g)
2
1
2
+ 𝐼2 (g) ⇌ 𝐼Cl (g)
Kc = 454
What is the concentration of iodine monochloride, 𝐼Cl?
A.
454
0.02
B. 454 × 0.02
C.
454
0.04
D. 454 × 0.04
19.
. The pH of solution A is 1 and the pH of solution B is 2. Which is a correct statement?
A. [H+(aq)] in B is ten times that in A.
B. [H+(aq)] in A is ten times that in B.
C. [H+(aq)] in A is twice that in B.
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D. [H+(aq)] in A is half that in B.
20.
Which substance will not produce copper(II) chloride when added to dilute hydrochloric acid?
A. 𝐶𝑢 (𝑠)
B. 𝐶𝑢(𝑂𝐻)2 (𝑠)
C. 𝐶𝑢𝐶𝑂3 (𝑠)
D. 𝐶𝑢𝑂 (𝑠)
21. How many structural isomers are there with the molecular formula C6H14?
A. 3
B. 4
C. 5
D. 6
22.
What is the major reason why the pH of unpolluted rain is less than 7?
A. methane
B. carbon dioxide
C. nitrogen oxides
D. sulfur dioxide
23. Equal masses of excess magnesium metal were added to separate solutions of hydrochloric acid.
The volume of hydrogen evolved was measured at regular time intervals and the results presented
graphically. Which curve best represents the results obtained for the different solutions of
hydrochloric acid shown below?
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A
B
C
D
24.
50cm3 of
2mol dm-3HCL
50cm3 of
1mol dm-3HCL
100cm3 of
1 mol dm-3HCL
IV
I
III
III
III
III
I
III
II
II
II
II
Which trends are correct across period 3 (from Na to Cl)?
I. Atomic radius decreases
II. Melting point increases
III. First ionization energy increases
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
25.
Which product will be obtained at the anode (positive electrode) when molten NaCl is
electrolysed?
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A. Na (l)
B. Cl (g)
C. Cl2 (g)
D. Na (s)
26.
What is the order of increasing boiling point for the isomers of C5H12?
A. CH3CH2CH2CH2CH3 < CH3CH(CH3)CH2CH3 < CH3C(CH3)3
B. CH3C(CH3)3 < CH3CH2CH2CH2CH3 < CH3CH(CH3)CH2CH3
C. CH3C(CH3)3 < CH3CH(CH3)CH2CH3 < CH3CH2CH2CH2CH3
D. CH3CH(CH3)CH2CH3 < CH3C(CH3)3 < CH3CH2CH2CH2CH3
27. A student obtained the following data to calculate 𝑞, using 𝑞 = 𝑚𝑐𝛥𝑇.
𝑚 = 20.2 𝑔 ± 0.2 𝑔
𝛥𝑇 = 10∘ 𝐶 ± 1∘ 𝐶
𝑐 = 4.18 𝐽 𝑔−1 𝐾 −1
What is the percentage uncertainty in the calculated value of 𝑞?
A. 0.2
B. 1.2
C. 11
D. 14
28. Which is a secondary halogenoalkane?
A. 2-iodobutane
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B. 1-chloropropane
C. 2-chloro-2-methylpropane
D. 1,2-dibromoethane
29. The graph shows the reaction profile for the hydrogenation of ethene using a nickel catalyst.
Which row contains the corrects descriptions for x, y and z?
A. 4
B. 2
C. 1
D. 3
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30.
Which compound produces this mass spectrum?
[Spectral Database for Organic Compounds, SDBS. SDBS Compounds and Spectral Search. [graph] Available at:
https://sdbs.db.aist.go.jp [Accessed 3 January 2019].]
A. Chloroethanol
B. Methoxy ethane
C. Chloroethane
D. Ethanoic acid
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