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1. What is the sum of all coefficients when the

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1.
What is the sum of all coefficients when the following equation is balanced using the smallest
possible whole numbers?
__ C2H2 + __O2 в†’ __CO2 + __H2O
A.
5
B.
7
C.
11
D.
13
(Total 1 mark)
2.
1.7 g of NaNO3 (Mr = 85) is dissolved in water to prepare 0.20 dm3 of solution. What is the
concentration of the resulting solution in mol dm–3?
A.
0.01
B.
0.1
C.
0.2
D.
1.0
(Total 1 mark)
3.
How many molecules are present in a drop of ethanol, C2H5OH, of mass 2.3 × 10–3 g?
(L = 6.0 × 1023 mol–1)
A.
3.0 Г— 10 19
B.
3.0 Г— 1020
C.
6.0 Г— 1020
D.
6.0 Г— 1026
(Total 1 mark)
4.
Which sample has the greatest mass?
A.
1 mol of SO2
B.
2 mol of N2O
C.
2 mol of Ar
D.
4 mol of NH3
(Total 1 mark)
5.
The relative molecular mass of a gas is 56 and its empirical formula is CH2. What is the
molecular formula of the gas?
A.
CH2
B.
C2H4
C.
C3H6
D.
C4H8
(Total 1 mark)
6.
Ethanol is used as a component in fuel for some vehicles. One fuel mixture contains 10 % by
mass of ethanol in unleaded petrol (gasoline). This mixture is often referred to as Gasohol E10.
(a)
Assume that the other 90 % by mass of Gasohol E10 is octane. 1.00 kg of this fuel
mixture was burned.
CH3CH2OH(l) + 3O2(g) в†’ 2CO2(g) + 3H2O(l)
1
C8H18(l) + 12 O2(g) в†’ 8CO2(g) + 9H2O(l)
2
(i)
∆HO = –1367 kJ mol–1
∆HO = –5470 kJ mol–1
Calculate the mass, in g, of ethanol and octane in 1.00 kg of the fuel mixture.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Calculate the amount, in mol, of ethanol and octane in 1.00 kg of the fuel mixture.
...........................................................................................................................
...........................................................................................................................
(1)
(iii)
Calculate the total amount of energy, in kJ, released when 1.00 kg of the fuel
mixture is completely burned.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(b)
If the fuel blend was vaporized before combustion, predict whether the amount of energy
released would be greater, less or the same. Explain your answer.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(Total 7 marks)
7.
What mass, in g, of hydrogen is formed when 3 mol of aluminium react with excess
hydrochloric acid according to the following equation?
2Al(s) + 6HCl(aq) в†’ 2AlCl3(aq) + 3H2(g)
A.
3.0
B.
4.5
C.
6.0
D.
9.0
(Total 1 mark)
8.
What is the total number of hydrogen atoms in 1.0 mol of benzamide, C6H5CONH2?
A.
7
B.
6.0 Г— 1023
C.
3.0 Г— 1024
D.
4.2 Г— 1024
(Total 1 mark)
9.
What is the sum of the coefficients for the equation when balanced using the smallest possible
whole numbers?
__N2H4(g) + __O2(g) в†’ __NO2(g) + __H2O(g)
A.
5
B.
6
C.
7
D.
8
(Total 1 mark)
10.
Chloroethene, C2H3Cl, reacts with oxygen according to the equation below.
2C2H3Cl(g) + 5O2(g) в†’ 4CO2(g) + 2H2O(g) + 2HCl(g)
What is the amount, in mol, of H2O produced when 10.0 mol of C2H3Cl and 10.0 mol of O2 are
mixed together, and the above reaction goes to completion?
A.
4.00
B.
8.00
C.
10.0
D.
20.0
(Total 1 mark)
11.
A fixed mass of gas has a certain volume at a temperature of 50 В°C. What temperature is
required to double its volume while keeping the pressure constant?
A.
100 K
B.
323 K
C.
373 K
D.
646 K
(Total 1 mark)
12.
What is the concentration of NaCl, in mol dm–3, when 10.0 cm3 of 0.200 mol dm–3 NaCl
solution is added to 30.0 cm3 of 0.600 mol dm–3 NaCl solution?
A.
0.450
B.
0.300
C.
0.500
D.
0.800
(Total 1 mark)
13.
Which amount of the following compounds contains the least number of ions?
A.
2 mol of NaOH
B.
1 mol of NH4Cl
C.
2 mol of CaCl2
D.
1 mol of Al2O3
(Total 1 mark)
14.
What is the approximate molar mass, in g mol–1, of MgSO4•7H2O?
A.
120
B.
130
C.
138
D.
246
(Total 1 mark)
15.
Which is both an empirical and a molecular formula?
A.
C5H12
B.
C5H10
C.
C4H8
D.
C4H10
(Total 1 mark)
16.
12 molecules of hydrogen gas, H2(g), and 5 molecules of oxygen gas, O2(g), were mixed
together under conditions which allowed the reaction to go to completion, according to the
following equation.
2H2(g) + O2(g) в†’ 2H2O(g)
The following diagram represents the mixture of reactants.
Which diagram represents the reaction mixture when the reaction was complete?
A.
B.
C.
D.
(Total 1 mark)
17.
Brass is a copper containing alloy with many uses. An analysis is carried out to determine the
percentage of copper present in three identical samples of brass. The reactions involved in this
analysis are shown below.
Step 1: Cu(s) + 2HNO3(aq) + 2H+(aq) в†’ Cu2+(aq) + 2NO2(g) + 2H2O(l)
Step 2: 4I–(aq) + 2Cu2+(aq) → 2CuI(s) + I2(aq)
Step 3: I2(aq) + 2S2O32–(aq) → 2I–(aq) + S4O62–(aq)
(a)
(i)
Deduce the change in the oxidation numbers of copper and nitrogen in step 1.
Copper:
...........................................................................................................................
Nitrogen:
...........................................................................................................................
(2)
(ii)
Identify the oxidizing agent in step 1.
...........................................................................................................................
(1)
(b)
A student carried out this experiment three times, with three identical small brass nails,
and obtained the following results.
Mass of brass = 0.456 g В± 0.001 g
Titre
1
2
3
Initial volume of 0.100 mol dm–3 S2O32– (± 0.05 cm3)
0.00
0.00
0.00
Final volume of 0.100 mol dm–3 S2O32– (± 0.05 cm3)
28.50
28.60
28.40
Volume added of 0.100 mol dm–3 S2O32– (± 0.10 cm3)
28.50
28.60
28.40
Average volume added of 0.100 mol dm–3 S2O32–(± 0.10
cm3)
(i)
28.50
Calculate the average amount, in mol, of S2O32– added in step 3.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Calculate the amount, in mol, of copper present in the brass.
...........................................................................................................................
...........................................................................................................................
(1)
(iii)
Calculate the mass of copper in the brass.
...........................................................................................................................
...........................................................................................................................
(1)
(iv)
Calculate the percentage by mass of copper in the brass.
...........................................................................................................................
...........................................................................................................................
(1)
(v)
The manufacturers claim that the sample of brass contains 44.2 % copper by mass.
Determine the percentage error in the result.
...........................................................................................................................
...........................................................................................................................
(1)
(c)
With reference to its metallic structure, describe how brass conducts electricity.
......................................................................................................................................
......................................................................................................................................
(1)
(Total 10 marks)
18.
What is the coefficient of Fe3O4 when the following equation is balanced using the lowest
whole numbers?
__ Al(s) + __ Fe3O4(s) в†’ __ Al2O3(s) + __ Fe(s)
A.
2
B.
3
C.
4
D.
5
(Total 1 mark)
19.
What is the mass, in g, of one molecule of ethane, C2H6?
A.
3.0 × 10–23
B.
5.0 × 10–23
C.
30
D.
1.8 Г— 1025
(Total 1 mark)
20.
Which molecular formula is also an empirical formula?
A.
PCl3
B.
C2H4
C.
H2O2
D.
C6H12O6
(Total 1 mark)
21.
Which of the following is consistent with Avogadro’s law?
A.
P
= constant (V, n constant)
T
B.
V
= constant (P, n constant)
T
C.
Vn = constant (P, T constant)
D.
V
= constant (P, T constant)
n
(Total 1 mark)
22.
The percentage by mass of calcium carbonate in eggshell was determined by adding excess
hydrochloric acid to ensure that all the calcium carbonate had reacted. The excess acid left was
then titrated with aqueous sodium hydroxide.
(a)
A student added 27.20 cm3 of 0.200 mol dm–3 HCl to 0.188 g of eggshell. Calculate the
amount, in mol, of HCl added.
......................................................................................................................................
......................................................................................................................................
(1)
(b)
The excess acid requires 23.80 cm3 of 0.100 mol dm–3 NaOH for neutralization.
Calculate the amount, in mol, of acid that is in excess.
......................................................................................................................................
......................................................................................................................................
(1)
(c)
Determine the amount, in mol, of HCl that reacted with the calcium carbonate in the
eggshell.
......................................................................................................................................
......................................................................................................................................
(1)
(d)
State the equation for the reaction of HCl with the calcium carbonate in the eggshell.
......................................................................................................................................
......................................................................................................................................
(2)
(e)
Determine the amount, in mol, of calcium carbonate in the sample of the eggshell.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(f)
Calculate the mass and the percentage by mass of calcium carbonate in the eggshell
sample.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(g)
Deduce one assumption made in arriving at the percentage of calcium carbonate in the
eggshell sample.
......................................................................................................................................
......................................................................................................................................
(1)
(Total 11 marks)
23.
6.0 mol of aluminium reacts with oxygen to form aluminium oxide. What is the amount of
oxygen, in mol, needed for complete reaction?
4Al(s) + 3O2(g) в†’ 2Al2O3(s)
A.
1.5
B.
3.0
C.
4.5
D.
6.0
(Total 1 mark)
24.
What is the total number of nitrogen atoms in two mol of NH4NO3?
A.
4
B.
6.02 Г— 1023
C.
1.20 Г— 1024
D.
2.41 Г— 1024
(Total 1 mark)
25.
On analysis, a compound with molar mass 60 g mol–1 was found to contain 12 g of carbon, 2 g
of hydrogen and 16 g of oxygen. What is the molecular formula of the compound?
A.
CH2O
B.
CH4O
C.
C2H4O
D.
C2H4O2
(Total 1 mark)
26.
Equal masses of the metals Na, Mg, Ca and Ag are added to separate samples of excess
HCl(aq).
Which metal produces the greatest total volume of H2(g)?
A.
Na
B.
Mg
C.
Ca
D.
Ag
(Total 1 mark)
27.
The graph below represents the relationship between two variables in a fixed amount of gas.
Which variables could be represented by each axis?
x-axis
y-axis
A.
pressure
temperature
B.
volume
temperature
C.
pressure
volume
D.
temperature
volume
(Total 1 mark)
28.
8.5 g of NH3 are dissolved in H2O to prepare a 500 cm3 solution. Which statements are correct?
I.
NH3 is the solute and H2O is the solution
II.
The concentration of the solution is 17 g dm–3
III.
[NH3] = 1.0 mol dm–3
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
29.
Consider the following sequence of reactions.
reaction 1
reaction 2
reaction 3
RCH3 п‚ѕп‚ѕ
п‚ѕп‚ѕп‚® RCH2Br п‚ѕп‚ѕ
п‚ѕп‚ѕп‚® RCH2OH п‚ѕп‚ѕ
п‚ѕп‚ѕп‚® RCOOH
RCH3 is an unknown alkane in which R represents an alkyl group.
(a)
The alkane contains 81.7 % by mass of carbon. Determine its empirical formula, showing
your working.
(3)
(b)
Equal volumes of carbon dioxide and the unknown alkane are found to have the same
mass, measured to an accuracy of two significant figures, at the same temperature and
pressure. Deduce the molecular formula of the alkane.
(1)
(c)
(i)
State the reagent and conditions needed for reaction 1.
(2)
(ii)
State the reagent(s) and conditions needed for reaction 3.
(2)
(d)
Reaction 1 involves a free-radical mechanism. Describe the stepwise mechanism, by
giving equations to represent the initiation, propagation and termination steps.
(4)
(e)
The mechanism in reaction 2 is described as SN2.
(i)
State the meaning of each of the symbols in SN2.
(1)
(ii)
Explain the mechanism of this reaction using curly arrows to show the movement
of electron pairs, and draw the structure of the transition state.
(3)
(Total 16 marks)
30.
300 cm3 of water is added to a solution of 200 cm3 of 0.5 mol dm–3 sodium chloride. What is
the concentration of sodium chloride in the new solution?
A.
0.05 mol dm–3
B.
0.1 mol dm–3
C.
0.2 mol dm–3
D.
0.3 mol dm–3
(Total 1 mark)
31.
The molar mass of a compound is approximately 56 g mol–1. Which formula is possible for this
compound?
A.
NaNO3
B.
AgOH
C.
MgO
D.
KOH
(Total 1 mark)
32.
Which compound has the empirical formula with the largest mass?
A.
C2H6
B.
C2H4
C.
C2H2
D.
C3H6
(Total 1 mark)
33.
What is the coefficient for O2(g) when the equation for the combustion of 1 mole of pentane is
balanced?
C5H12(g) + _O2(g) в†’ _CO2(g) + _H2O(g)
A.
5
B.
6
C.
8
D.
16
(Total 1 mark)
34.
What is the maximum mass, in g, of magnesium oxide that can be obtained from the reaction of
oxygen with 2.4 g of magnesium?
A.
2.4
B.
3.0
C.
4.0
D.
5.6
(Total 1 mark)
35.
5 dm3 of carbon monoxide, CO(g), and 2 dm3 of oxygen, O2(g), at the same temperature and
pressure are mixed together. Assuming complete reaction according to the equation given, what
is the maximum volume of carbon dioxide, CO2(g), in dm3, that can be formed?
2CO(g) + O2(g) в†’ 2CO2
A.
3
B.
4
C.
5
D.
7
(Total 1 mark)
36.
Which statement about solutions is correct?
A.
When vitamin D dissolves in fat, vitamin D is the solvent and fat is the solute.
B.
In a solution of NaCl in water, NaCl is the solute and water is the solvent.
C.
An aqueous solution consists of water dissolved in a solute.
D.
The concentration of a solution is the amount of solvent dissolved in 1 dm3 of solution.
(Total 1 mark)
37.
Biodiesel makes use of plants’ ability to fix atmospheric carbon by photosynthesis.
Many companies and individuals are now using biodiesel as a fuel in order to reduce their
carbon footprint. Biodiesel can be synthesized from vegetable oil according to the following
reaction.
(a)
Identify the organic functional group present in both vegetable oil and biodiesel.
......................................................................................................................................
(1)
(b)
For part of her extended essay investigation into the efficiency of the process, a student
reacted a pure sample of a vegetable oil (where R = C17H33) with methanol.
The raw data recorded for the reaction is below.
Mass of oil
Mass of methanol
Mass of sodium hydroxide
Mass of biodiesel produced
= 1013.0 g
= 200.0 g
=
3.5 g
= 811.0 g
The relative molecular mass of the oil used by the student is 885.6. Calculate the amount
(in moles) of the oil and the methanol used, and hence the amount (in moles) of excess
methanol.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(c)
The reversible arrows in the equation indicate that the production of biodiesel is an
equilibrium process.
(i)
State what is meant by the term dynamic equilibrium.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Using the abbreviations [vegetable oil], [methanol], [glycerol] and [biodiesel]
deduce the equilibrium constant expression (Kc) for this reaction.
(1)
(iii)
Suggest a reason why excess methanol is used in this process.
...........................................................................................................................
...........................................................................................................................
(1)
(iv)
State and explain the effect that the addition of the sodium hydroxide catalyst will
have on the position of equilibrium.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(d)
The reactants had to be stirred vigorously because they formed two distinct layers in the
reaction vessel. Explain why they form two distinct layers and why stirring increases the
rate of reaction.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(e)
Calculate the percentage yield of biodiesel obtained in this process.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(f)
When biodiesel is combusted it produces carbon dioxide. Explain why the use of
biodiesel as a fuel does not significantly contribute to global warming.
......................................................................................................................................
......................................................................................................................................
(1)
(Total 14 marks)
38.
The percentage of iron(II) ions, Fe2+, in a vitamin tablet can be estimated by dissolving the
tablet in dilute sulfuric acid and titrating with standard potassium manganate(VII) solution,
KMnO4(aq). During the process iron(II) is oxidized to iron(III) and the manganate(VII) ion is
reduced to the manganese(II) ion, Mn2+(aq). It was found that one tablet with a mass of 1.43 g
required 11.6 cm3 of 2.00 × 10–2 mol dm–3 KMnO4(aq) to reach the end-point.
(a)
(i)
State the half-equation for the oxidation of the iron(II) ions.
...........................................................................................................................
(1)
(ii)
State the half-equation for the reduction of the MnO4– ions in acidic solution.
...........................................................................................................................
(1)
(iii)
Deduce the overall redox equation for the reaction.
...........................................................................................................................
(1)
(b)
(i)
Calculate the amount, in moles, of MnO4– ions present in 11.6 cm3 of
2.00 × 10–2 mol dm–3 KMnO4(aq).
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Calculate the amount, in moles, of Fe2+ ions present in the vitamin tablet.
...........................................................................................................................
...........................................................................................................................
(1)
(iii)
Determine the percentage by mass of Fe2+ ions present in the vitamin tablet.
...........................................................................................................................
...........................................................................................................................
(2)
(Total 7 marks)
39.
What is the number of oxygen atoms in one mole of CuSO4•5H2O?
A.
5
B.
9
C.
6.0 Г— 1023
D.
5.4 Г— 1024
(Total 1 mark)
40.
Which sample has the greatest mass?
A.
6.0 Г— 1025 molecules of hydrogen
B.
5.0 mol of neon atoms
C.
1.2 Г— 1024 atoms of silver
D.
1.7 Г— 102 g of iron
(Total 1 mark)
41.
What volume of sulfur trioxide, in cm3, can be prepared using 40 cm3 sulfur dioxide and 20
cm3 oxygen gas by the following reaction? Assume all volumes are measured at the same
temperature and pressure.
2SO2(g) + O2(g) в†’ 2SO3(g)
A.
20
B.
40
C.
60
D.
80
(Total 1 mark)
42.
Which sample of nitrogen gas, N2, contains the greatest number of nitrogen molecules?
A.
1.4 g N2
B.
1.4 dm3 of N2 at 1.01 Г— 105 Pa and 273 K
C.
1.4 Г— 1023 N2 molecules
D.
1.4 mol N2
(Total 1 mark)
43.
Aspirin, one of the most widely used drugs in the world, can be prepared according to the
equation given below.
(a)
State the names of the three organic functional groups in aspirin.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(b)
A student reacted some salicylic acid with excess ethanoic anhydride. Impure solid
aspirin was obtained by filtering the reaction mixture. Pure aspirin was obtained by
recrystallization. The following table shows the data recorded by the student.
(i)
Mass of salicylic acid used
3.15 В± 0.02 g
Mass of pure aspirin obtained
2.50 В± 0.02 g
Determine the amount, in mol, of salicylic acid, C6H4(OH)COOH, used.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Calculate the theoretical yield, in g, of aspirin, C6H4(OCOCH3)COOH.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
Determine the percentage yield of pure aspirin.
...........................................................................................................................
...........................................................................................................................
(1)
(iv)
State the number of significant figures associated with the mass of pure aspirin
obtained, and calculate the percentage uncertainty associated with this mass.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(v)
Another student repeated the experiment and obtained an experimental yield of
150 %. The teacher checked the calculations and found no errors. Comment on the
result.
...........................................................................................................................
...........................................................................................................................
(1)
(Total 11 marks)
44.
Smog is common in cities throughout the world. One component of smog is PAN
(peroxyacylnitrate) which consists of 20.2 % C, 11.4 % N, 65.9 % O and 2.50 % H by mass.
Determine the empirical formula of PAN, showing your working.
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(Total 3 marks)
45.
Which non-metal forms an oxide XO2 with a relative molecular mass of 60?
A.
C
B.
N
C.
Si
D.
S
(Total 1 mark)
46.
How many oxygen atoms are there in 0.20 mol of ethanoic acid, CH3COOH?
A.
1.2 Г— 1023
B.
2.4 Г— 1023
C.
3.0 Г— 1024
D.
6.0 Г— 1024
(Total 1 mark)
47.
4.00 mol of a hydrocarbon with an empirical formula of CH2 has a mass of 280 g. What is the
molecular formula of this compound?
A.
C2H4
B.
C3H6
C.
C4H8
D.
C5H10
(Total 1 mark)
48.
What will be the concentration of sulfate ions in mol dm–3 when 0.20 mol of KAl(SO4)2 is
dissolved in water to give 100 cm3 of aqueous solution?
A.
0.2
B.
1.0
C.
2.0
D.
4.0
(Total 1 mark)
49.
The volume of an ideal gas at 27.0 В°C is increased from 3.00 dm3 to 6.00 dm3. At what
temperature, in В°C, will the gas have the original pressure?
A.
13.5
B.
54.0
C.
327
D.
600
(Total 1 mark)
50.
The data below is from an experiment used to determine the percentage of iron present in a
sample of iron ore. This sample was dissolved in acid and all of the iron was converted to Fe2+.
The resulting solution was titrated with a standard solution of potassium manganate(VII),
KMnO4. This procedure was carried out three times. In acidic solution, MnO4– reacts with Fe2+
ions to form Mn2+ and Fe3+ and the end point is indicated by a slight pink colour.
titre
1
2
3
initial burette reading / cm3
1.00
23.60
10.00
Final burette reading / cm3
24.60
46.10
32.50
Mass of iron ore / g
3.682 × 10–1
concentration of KMnO4 solution / mol dm–3
2.152 × 10–2
(a)
Deduce the balanced redox equation for this reaction in acidic solution.
......................................................................................................................................
......................................................................................................................................
(2)
(b)
Identify the reducing agent in the reaction.
......................................................................................................................................
(1)
(c)
Calculate the amount, in moles, of MnO4– used in the titration.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(d)
Calculate the amount, in moles, of Fe present in the 3.682 × 10–1 g sample of iron ore.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(e)
Determine the percentage by mass of Fe present in the 3.682 × 10–1 g sample of iron ore.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(Total 9 marks)
51.
Which coefficients would balance this equation?
__ MnO2 + __ HCl в†’ __ MnCl2 + __ Cl2 + __ H2O
MnO2
HCl
MnCl2
Cl2
H 2O
A.
1
2
1
1
1
B.
1
3
1
1
1
C.
1
4
1
1
2
D.
1
4
1
2
2
(Total 1 mark)
52.
What volume of carbon dioxide, in dm3 under standard conditions, is formed when 7.00 g of
ethene (C2H4, Mr = 28.1) undergoes complete combustion?
A.
22.4 п‚ґ 28.1
7.00
B.
22.4 п‚ґ 7.00
28.1
C.
2 п‚ґ 22.4 п‚ґ 28.1
7.00
D.
2 п‚ґ 22.4 п‚ґ 7.00
28.1
(Total 1 mark)
53.
How many hydrogen atoms are in one mole of ethanol, C2H5OH?
A.
1.00Г—1023
B.
3.61Г—1024
C.
5.00
D.
6.00
(Total 1 mark)
54.
What is the coefficient for H2SO4(aq) when the following equation is balanced, using the
smallest possible integers?
__Mg3N2(s) + __H2SO4(aq) в†’ __MgSO4(aq) + __(NH4)2SO4(aq)
A.
1
B.
3
C.
4
D.
7
(Total 1 mark)
55.
Air bags in cars inflate when sodium azide decomposes to form sodium and nitrogen:
2NaN3(s) в†’ 2Na(s) + 3N2(g)
Calculate the amount, in moles, of nitrogen gas produced by the decomposition of 2.52 mol of
NaN3(s).
A.
1.68
B.
2.52
C.
3.78
D.
7.56
(Total 1 mark)
56.
What volume, in cm3, of 0.200 mol dm–3 HCl(aq) is required to neutralize 25.0 cm3 of 0.200
mol dm–3 Ba(OH)2(aq)?
A.
12.5
B.
25.0
C.
50.0
D.
75.0
(Total 1 mark)
57.
0.600 mol of aluminium hydroxide is mixed with 0.600 mol of sulfuric acid, and the following
reaction occurs:
2Al(OH)3(s) + 3H2SO4(aq) в†’ Al2(SO4)3(aq) + 6H2O(l)
(a)
Determine the limiting reactant.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
Calculate the mass of Al2(SO4)3 produced.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
Determine the amount (in mol) of excess reactant that remains.
.....................................................................................................................................
.....................................................................................................................................
(1)
(d)
Define a BrГёnsted-Lowry acid and a Lewis base.
BrГёnsted-Lowry acid
.....................................................................................................................................
Lewis base
.....................................................................................................................................
(2)
(e)
H2SO4(aq) is a strong acid. State the name and the formula of any weak acid.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 8 marks)
58.
A toxic gas, A, consists of 53.8 % nitrogen and 46.2 % carbon by mass. At 273 K and
1.01Г—105 Pa, 1.048 g of A occupies 462 cm3. Determine the empirical formula of A.
Calculate the molar mass of the compound and determine its molecular structure.
(Total 3 marks)
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