1.
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)
2.
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 × 10 19
B.
3.0 × 1020
C.
6.0 × 1020
D.
6.0 × 1026
(Total 1 mark)
3.
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)
4.
What is the sum of the coefficients for the equation when balanced using the smallest possible
whole numbers?
__N2H4(g) + __O2(g) → __NO2(g) + __H2O(g)
A.
5
B.
6
C.
7
D.
8
(Total 1 mark)
5.
A fixed mass of gas has a certain volume at a temperature of 50 °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)
6.
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)
7.
What is the approximate molar mass, in g mol–1, of MgSO4•7H2O?
A.
120
B.
130
C.
138
D.
246
(Total 1 mark)
8.
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) → 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)
9.
Which statement about the numbers of protons, electrons and neutrons in an atom is always
correct?
A.
The number of neutrons minus the number of electrons is zero.
B.
The number of protons plus the number of neutrons equals the number of electrons.
C.
The number of protons equals the number of electrons.
D.
The number of neutrons equals the number of protons.
(Total 1 mark)
10.
In the emission spectrum of hydrogen, which electronic transition would produce a line in the
visible region of the electromagnetic spectrum?
A.
n = 2 →n = 1
B.
n=3→n=2
C.
n=2→n=3
D.
n=∞→n=1
(Total 1 mark)
11.
Which of the following is an isotope of
A.
24
12
Mg 2 
B.
26
12
Mg
C.
42
13 Mg
D.
26
13 Mg
24
12 Mg?
(Total 1 mark)
12.
How many protons, neutrons and electrons are present in each atom of 31P?
Protons
Neutrons
Electrons
A.
16
15
16
B.
15
16
15
C.
15
31
15
D.
16
31
16
(Total 1 mark)
13.
What is the relative atomic mass of an element with the following mass spectrum?
A.
24
B.
25
C.
26
D.
27
(Total 1 mark)
14.
Which species have the same number of electrons?
I.
S2–
II.
Cl–
III.
Ne
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
15.
Which species has 54 electrons and 52 protons?
A.
128
2
52 Te
B.
132
54
Xe 2 
C.
132
54
Xe 2 
D.
128
2
52 Te
(Total 1 mark)
16.
What is the correct Lewis structure for hypochlorous acid, a compound containing chlorine,
hydrogen and oxygen?
A.
.. ..
: Cl : O : H :
.. ..
B.
..
..
: Cl : H : O :
..
..
C.
.. ..
: Cl : O : H
.. ..
D.
.. ..
O : Cl : H
.. ..
(Total 1 mark)
17.
Which is the best description of the bonding present in the ammonium ion, NH 4+?
A.
Sharing of electrons between atoms
B.
Electrostatic attraction between ions
C.
Electrostatic attraction between positive ions and delocalized electrons
D.
Sharing of electrons between atoms and electrostatic attraction between ions
(Total 1 mark)
18.
Which pair of compounds is arranged in correct order of relative boiling points?
Lower Boiling Point
Higher Boiling Point
A.
H2S
H2O
B.
NH3
PH3
C.
HF
HCl
D.
CH3COOH
CH3CH2OH
(Total 1 mark)
19.
Which molecule is polar?
A.
CH2Cl2
B.
BCl3
C.
Cl2
D.
CCl4
(Total 1 mark)
20.
What is the shape of the ammonia molecule, NH3?
A.
Trigonal planar
B.
Trigonal pyramidal
C.
Linear
D.
V-shaped (bent)
(Total 1 mark)
21.
Which property generally decreases across period 3?
A.
Atomic number
B.
Electronegativity
C.
Atomic radius
D.
First ionization energy
(Total 1 mark)
22.
Which property increases down group 1?
A.
First ionization energy
B.
Melting point
C.
Reactivity
D.
Electronegativity
(Total 1 mark)
23.
Which statements about the periodic table are correct?
I.
Elements in period 3 have similar chemical properties.
II.
Elements in group 7 show a gradual change in physical properties.
III.
The position of an element in period 3 is related to the number of electrons in the
highest occupied energy level.
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
24.
Which oxides produce an acidic solution when added to water?
I.
P4O10
II.
MgO
III.
SO3
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
25.
An element is in group 4 and period 3 of the periodic table. How many electrons are in the
highest occupied energy level of an atom of this element?
A.
3
B.
4
C.
12
D.
14
(Total 1 mark)
26.
An atom of an element contains 19 electrons. In which group of the periodic table does it
occur?
A.
1
B.
2
C.
5
D.
7
(Total 1 mark)
27.
Which series is arranged in order of increasing radius?
A.
Ca2+ < Cl– < K+
B.
K+ < Ca2+ < Cl–
C.
Ca2+ < K+ < Cl–
D.
Cl– < K+ < Ca2+
(Total 1 mark)
28.
The equilibrium between nitrogen dioxide, NO2, and dinitrogen tetroxide, N2O4, is shown
below.
2NO2(g)
N2O4(g)
Kc = 0.01
What happens when the volume of a mixture at equilibrium is decreased at a constant
temperature?
I.
The value of Kc increases
II.
More N2O4 is formed
III.
The ratio of
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
[ NO 2 ]
decreases
[N 2 O 4 ]
(Total 1 mark)
29.
Which statement about chemical equilibria implies they are dynamic?
A.
The position of equilibrium constantly changes.
B.
The rates of forward and backward reactions change.
C.
The reactants and products continue to react.
D.
The concentrations of the reactants and products continue to change.
(Total 1 mark)
30.
For the following reaction Kc = 1.0 × 10–5 at 30 °C.
2NOCl(g)
2NO(g) + Cl2(g)
Which relationship is correct at equilibrium at this temperature?
A.
The concentration of NO equals the concentration of NOCl.
B.
The concentration of NOCl is double the concentration of Cl 2.
C.
The concentration of NOCl is much greater than the concentration of Cl 2.
D.
The concentration of NO is much greater than the concentration of NOCl.
(Total 1 mark)
31.
What effect will an increase in temperature have on the Kc value and the position of equilibrium
in the following reaction?
N2(g) + 3H2(g)
2NH3(g)
Kc
Equilibrium position
A.
increases
shifts to the right
B.
decreases
shifts to the left
C.
increases
shifts to the left
D.
decreases
shifts to the right
ΔH = –92 kJ
(Total 1 mark)
32.
An increase in temperature increases the amount of chlorine present in the following
equilibrium.
PCl5(s)
PCl3(l) + Cl2(g)
What is the best explanation for this?
A.
The higher temperature increases the rate of the forward reaction only.
B.
The higher temperature increases the rate of the reverse reaction only.
C.
The higher temperature increases the rate of both reactions but the forward reaction is
affected more than the reverse.
D.
The higher temperature increases the rate of both reactions but the reverse reaction is
affected more than the forward.
(Total 1 mark)
33.
Which statements describe the action of a catalyst?
I.
It does not alter the ∆H for a reaction.
II.
It increases the Ea for the reaction.
III.
It alters the mechanism (pathway) of a reaction.
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
34.
At 25 °C, 200 cm3 of 1.0 mol dm–3 nitric acid is added to 5.0 g of magnesium powder. If the
experiment is repeated using the same mass of magnesium powder, which conditions will result
in the same initial reaction rate?
Volume of HNO3 / cm3
Concentration of
HNO3 / mol dm–3
Temperature / °C
A.
200
2.0
25
B.
200
1.0
50
C.
100
2.0
25
D.
100
1.0
25
(Total 1 mark)
35.
A piece of zinc was added to aqueous nitric acid and the volume of hydrogen gas produced was
measured every minute. The results are plotted on the graph below.
Which graph would you expect if the same mass of powdered zinc was added to nitric acid with
the same concentration?
(Total 1 mark)
36.
What is the equilibrium constant expression for the reaction below?
2NO2(g)
A.
Kc =
[NO 2 ] 2
[N 2 O 4 ]
B.
Kc =
[N 2 O 4 ]
[NO 2 ]
C.
Kc =
[N 2 O 4 ]
2[NO 2 ]
D.
Kc =
N2O4(g)
[N 2 O 4 ]
[NO 2 ] 2
(Total 1 mark)
37.
Excess magnesium, was added to a beaker of aqueous hydrochloric acid. A graph of the mass of
the beaker and contents was plotted against time (line 1).
Mass
1
2
Time
What change in the experiment could give line 2?
A.
The same mass of magnesium in smaller pieces
B.
The same volume of a more concentrated solution of hydrochloric acid
C.
A lower temperature
D.
A more accurate instrument to measure the time
(Total 1 mark)
38.
What is the best definition of rate of reaction?
A.
The time it takes to use up all the reactants
B.
The rate at which all the reactants are used up
C.
The time it takes for one of the reactants to be used up
D.
The increase in concentration of a product per unit time
(Total 1 mark)
39.
When 100 cm3 of 1.0 mol dm–3 HCl is mixed with 100 cm3 of 1.0 mol dm–3 NaOH, the
temperature of the resulting solution increases by 5.0 °C. What will be the temperature change,
in °C, when 50 cm3 of these two solutions are mixed?
A.
2.5
B.
5.0
C.
10
D.
20
(Total 1 mark)
40.
Which statement about bonding is correct?
A.
Bond breaking is endothermic and requires energy.
B.
Bond breaking is endothermic and releases energy.
C.
Bond making is exothermic and requires energy.
D.
Bond making is endothermic and releases energy.
(Total 1 mark)
41.
Consider the following reactions.
Cu2O(s) +
1
O2(g) → 2CuO(s)
2
Cu2O(s) → Cu(s) + CuO(s)
∆HO = –144 kJ
∆HO = +11 kJ
What is the value of ∆HO, in kJ, for this reaction?
Cu(s) +
A.
–144 + 11
B.
+144 – 11
C.
–144 – 11
D.
+144 + 11
1
O2(g) → CuO(s)
2
(Total 1 mark)
42.
Which processes have a negative enthalpy change?
I.
2CH3OH(l) + 3O2(g) → 2CO2(g) + 4H2O(l)
II.
HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
III.
H2O(g) → H2O(l)
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
43.
Which types of reaction are always exothermic?
I.
Neutralization
II.
Decomposition
III.
Combustion
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
44.
A pure aluminium block with a mass of 10 g is heated so that its temperature increases from
20 °C to 50 °C . The specific heat capacity of aluminium is 8.99 × 10 –1 J g–1 K–1. Which
expression gives the heat energy change in kJ?
A.
10 × 8.99 × 10–1 × 303
B.
10 × 8.99 × 10–1 × 30
C.
10  8.99  10 1  303
1000
D.
10  8.99  10 1  30
1000
(Total 1 mark)
45.
When some solid barium hydroxide and solid ammonium thiosulfate were reacted together, the
temperature of the surroundings was observed to decrease from 15 ºC to – 4 ºC. What can be
deduced from this observation?
A.
The reaction is exothermic and ∆H is negative.
B.
The reaction is exothermic and ∆H is positive.
C.
The reaction is endothermic and ∆H is negative.
D.
The reaction is endothermic and ∆H is positive.
(Total 1 mark)
46.
In a reaction that occurs in 50 g of aqueous solution, the temperature of the reaction mixture
increases by 20 °C. If 0.10 mol of the limiting reagent is consumed, what is the enthalpy change
(in kJ mol–1) for the reaction? Assume the specific heat capacity of the solution
= 4.2 kJ kg–1 K–1.
A.
–0.10 × 50 × 4.2 × 20
B.
–0.10 × 0.050 × 4.2 × 20
C.
 50  4.2  20
0.10
D.
 0.050  4.2  20
0.10
(Total 1 mark)