Pakistan International School Jeddah – English Section
Department of chemistry
Academic Session 2023-2024
Mid-term Exam Review Pack
Name: __________________
Grade: Y10- _____
1.
substance
melting point
/ °C
boiling point
/ °C
electrical conductivity
as a solid
electrical conductivity
as a liquid
A
839
1484
good
good
B
–188
–42
poor
poor
C
776
1497
poor
good
117
78
poor
poor
E
1607
2227
poor
poor
F
–5
102
poor
good
D
–
(a) Which substance could be a metal?
[1]
(b) State all the substances that are liquid at room temperature.
[1]
(c) Which substance could have a macromolecular structure similar to that of silicon(IV) oxide?
[1]
(d) Which substance could be sodium chloride?
[1]
[Total: 4]
1
2.
[Total: 8]
(b) The diagrams represent the same number of particles of a gas in two containers, D and E,
which have different volumes. The two containers are at the same temperature.
D
E
In which container will the pressure be higher? Explain your answer.
....................................................................................................................................................
....................................................................................................................................................
.............................................................................................................................................. [1]
3. Complete the following table which gives the number of protons, electrons and neutrons in each
of the five particles.
particle
..............
56
26 Fe
..............
3+
70
31 Ga
..............
number of
protons
number of
electrons
number of
neutrons
19
19
20
..............
..............
..............
3
2
4
..............
..............
..............
34
36
45
[Total: 8]
4. (a)
b.
c.
Magnesium reacts with chlorine to form magnesium chloride, MgCl 2.
One physical property typical of ionic compounds, such as MgCl 2 , is that they are
soluble in water.
Give two other physical properties that are typical of ionic compounds.
1 ........................................................................................................................................
2 ........................................................................................................................................
[2]
d.
Aqueous silver nitrate is added to aqueous magnesium chloride.
A white precipitate forms.
Write an ionic equation for this reaction. Include state symbols.
.............................................................................................................................................. [2]
5 (a)
(b)
6
(a) Aqueous ammonium sulfate, (NH4 )2SO4, is warmed with aqueous sodium hydroxide.
The pungent-smelling gas ammonia, NH3, is produced.
Balance the equation for this reaction.
(NH4) 2SO4 + ......NaOH → ......NH3 + ......H2O + Na2SO4
[1]
(b) A 2.8 g sample of impure ammonium sulfate is found to contain 0.7 g of impurities.
Calculate the percentage of ammonium sulfate in this sample.
percentage of ammonium sulfate = .............................. % [1]
2
(c) Ammonia gas is prepared at the front of a laboratory.
The pungent smell of ammonia spreads throughout the laboratory slowly.
(i) Name the process that occurs when ammonia gas spreads throughout the laboratory.
....................................................................................
...................................................
(ii)
[1]
Explain, using ideas about particles, why ammonia gas spreads throughout the laboratory.
.............................................................................................................................................
.............................................................................................................................................
.............................................................................................................................................
....................................................................................................................................... [2]
(iii)
Explain why carbon dioxide gas, CO2 , will spread throughout the laboratory at a slower
rate than ammonia gas, NH3.
.............................................................................................................................................
....................................................................................................................................... [1]
(d) Ammonia is produced in the Haber process.
The equation for the reaction is shown.
N2(g) + 3H 2(g) → 2NH3 (g)
(i)
In the Haber process, a temperature of 450 °C and a pressure of 200 atmospheres are
used in the presence of finely‑divided iron.
A larger equilibrium yield of ammonia would be produced if a lower temperature and a
higher pressure are used.
Explain why a lower temperature and a higher pressure are not used.
lower temperature ...............................................................................................................
.............................................................................................................................................
higher pressure ...................................................................................................................
.............................................................................................................................................
[2]
(ii)
Suggest the pH of aqueous ammonia.
....................................................................................................................................... [1]
3
7
(a) Nitrogen reacts with fluorine to form nitrogen trifluoride, NF3.
(i)
The chemical equation can be represented as shown.
N≡N + 3 F–F 2 F–N–F
F
Some bond energies are shown in the table.
bond
bond energy in kJ / mol
N≡N
945
F–F
160
N–F
300
Calculate the energy change for the reaction between nitrogen and fluorine, using the
following steps:
●
energy taken in to break bonds
.............................. kJ
●
energy released when bonds are formed
.............................. kJ
●
energy change during the reaction.
.............................. kJ / mol
[3]
(ii)
Use your answer to (i) to deduce whether this reaction is endothermic or exothermic.
Explain your answer.
.............................................................................................................................................
....................................................................................................................................... [1]
4
(iii)
Complete the dot-and-cross diagram to show the electron arrangement in a molecule of
NF3.
Use dots for nitrogen electrons and crosses for fluorine electrons.
Show outer electrons only.
F
N
F
F
[3]
(b) Lithium nitride melts at 813 °C. Nitrogen trifluoride melts at –206 °C.
Explain in terms of attractive forces why lithium nitride has a much higher melting point than
nitrogen trifluoride.
In your answer refer to the types of attractive forces between particles and their relative
strengths.
....................................................................................................................................................
....................................................................................................................................................
....................................................................................................................................................
.............................................................................................................................................. [3]
5
8.
(vi)
Write the ionic half-equation for the formation of aluminium during the electrolysis.
...................................................................................................................................................
6
[1]
.
9
(i)
10. Three ways of making salts are
●
●
●
titration using a soluble base or carbonate
neutralisation using an insoluble base or carbonate
precipitation.
(a) Complete the following table of salt preparations.
method
titration
reagent 1
reagent 2
................................... ...................................
salt
sodium nitrate
................................... ...................................
neutralisation
nitric acid
...................................
copper(II) nitrate
...................................
precipitation
................................... ...................................
silver(I) chloride
................................... ...................................
neutralisation
sulfuric acid
zinc(II) carbonate
...................................
...................................
[6]
(b) (i) Write an ionic equation with state symbols for the preparation of silver(I) chloride.
.............................................................................................................................. [2]
(ii) Complete the following equation.
ZnCO3 + H2SO4 → ............... + ............... + ...............
[2]
[Total: 10]
8
11. Copper(II) oxide reacts with dilute hydrochloric acid.
CuO(s) + 2HCl (aq)
CuCl 2(aq) + H 2O(l)
6.00 g of copper( II) oxide were added to 50.0 cm3 of 1.00 mol / dm3 hydrochloric acid. This was an
excess of copper(II) oxide.
(a) (i)
Calculate the number of moles of copper(II) oxide added to the hydrochloric acid.
moles of copper(II) oxide = ............................. mol [2]
(ii)
Calculate the number of moles of hydrochloric acid used.
moles of hydrochloric acid = ............................. mol [1]
(iii)
Calculate the mass of copper(II) oxide that did not react.
mass of copper(II) oxide that did not react = ............................. g [2]
(b) Crystals of hydrated copper(II) chloride were obtained from the solution at the end of the
reaction.
The crystals had the following composition by mass: Cl, 41.52%; Cu, 37.43%; H, 2.34%;
O, 18.71%.
Calculate the empirical formula of the crystals.
empirical formula = ............................. [2]
10
12. (a) When aqueous sodium hydroxide is added to aqueous iron(II) sulfate, a precipitate forms.
(i) What colour is this precipitate?
....................................................................................................................................... [1]
(ii) Write the ionic equation for this reaction. Include state symbols.
....................................................................................................................................... [3]
....................................................................................
...................................................
(b)
(c) Deduce the charge on the iron ion in each of these compounds.
FeF3 ...........................................................................................................................................
Fe(NO3) 3 ....................................................................................................................................
[2]
11
13.
13
14.
At most temperatures, samples of nitrogen dioxide are equilibrium mixtures.
2NO2 (g)
dark brown
N2O 4(g)
pale yellow
(i) At 25 °C, the mixture contains 20 % of nitrogen dioxide. At 100 °C this has risen to
90 %. Is the forward reaction exothermic or endothermic?
Give a reason for your choice.
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
(ii) Explain why the colour of the equilibrium mixture becomes lighter when the pressure
on the mixture is increased.
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
14
15. Ammonia is a compound which only contains the elements nitrogen and hydrogen. It is a
weak base.
(a) (i) Define the term base.
.............................................................................................................................. [1]
(ii) Given aqueous solutions of ammonia and sodium hydroxide, both having a
concentration of 0.1 mol / dm 3, how could you show that ammonia is the weaker
base?
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
(b) The position of tin in the reactivity series is:
zinc
iron
tin
copper
For each of the following, decide if a reaction would occur. If there is a reaction,
complete the equation, otherwise write ‘no reaction’.
Cu + Sn2+ → ..........................................
Fe + Sn2+ → ..........................................
Sn + Zn2+ → ..........................................
15
[4]
16. 20.0 g of small lumps of calcium carbonate and 40 cm3 of hydrochloric acid, concentration
2.0 mol / dm3 , were placed in a flask on a top pan balance. The mass of the fl ask and contents
was recorded every minute.
.
cotton wool to prevent
drops of acid spray escaping
flask
40 cm3 of hydrochloric acid, 2.0 mol / dm3
20.0 g of small lumps of
calcium carbonate
balance
The mass of carbon dioxide given off was plotted against time.
mass of
carbon dioxide
0
0
time
CaCO3(s) + 2HCl (aq)  CaCl 2(aq) + H2O(l) + CO2(g)
In all the experiments mentioned in this question, the calcium carbonate was in excess.
(a) (i) Explain how you could determine the mass of carbon dioxide given off in the first five
minutes.
.............................................................................................................................. [1]
(ii) Label the graph F where the reaction rate is the fastest, S where it is slowing down
and 0 where the rate is zero.
[2]
(iii) Explain how the shape of the graph shows where the rate is fastest, where it is
slowing down and where the rate is zero.
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
(b) Sketch on the same graph, the line which would have been obtained if 20.0 g of small
lumps of calcium carbonate and 80 cm 3 of hydrochloric acid, concentration 1.0 mol / dm3,
had been used.
[2]
16
(c) Explain in terms of collisions between reacting particles each of the following.
(i) The reaction rate would be slower if 20.0 g of larger lumps of calcium carbonate and
40 cm3 of hydrochloric acid, concentration 2.0 mol / dm3 , were used.
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
(ii) The reaction rate would be faster if the experiment was carried out at a higher
temperature.
....................................................................................................................................
....................................................................................................................................
.............................................................................................................................. [2]
17.
17
88
87
–
91
93
96
Sg
protactinium
231
140
90
Th
thorium
232
139
89
Ac
actinium
–
cerium
lanthanum
59
Pa
91
141
praseodymium
Pr
58
Ce
57
–
La
–
238
uranium
U
92
144
neodymium
Nd
60
–
seaborgium
Db
Rf
–
neptunium
Np
93
–
promethium
Pm
61
–
bohrium
Bh
107
186
rhenium
actinoids
dubnium
–
75
tungsten
106
rutherfordium
Tc
technetium
–
plutonium
Pu
94
150
samarium
Sm
62
–
hassium
Hs
108
190
osmium
Os
76
101
ruthenium
28
Ni
–
americium
Am
95
152
europium
Eu
63
–
meitnerium
Mt
109
192
–
curium
Cm
96
157
gadolinium
Gd
64
–
darmstadtium
Ds
110
195
platinum
Pt
Ir
iridium
78
106
palladium
Pd
46
59
nickel
77
103
rhodium
Rh
45
Ru
59
44
43
56
Co
cobalt
55
Re
184
27
iron
Fe
26
manganese
Mn
25
W
74
105
181
tantalum
Ta
73
Mo
molybdenum
104
178
hafnium
Hf
72
Nb
niobium
42
52
chromium
Cr
24
89–103
89
Zr
zirconium
41
51
vanadium
V
23
relative atomic mass
29
30
2
VIII
Cu
–
berkelium
Bk
97
159
terbium
Tb
65
–
roentgenium
Rg
111
197
gold
Au
79
108
silver
Ag
47
64
copper
–
californium
Cf
98
163
dysprosium
Dy
66
–
copernicium
Cn
112
201
mercury
Hg
80
112
cadmium
Cd
48
65
zinc
Zn
B
N
–
einsteinium
Es
99
165
holmium
Ho
67
204
thallium
Tl
81
115
–
fermium
Fm
100
167
erbium
Er
68
–
flerovium
Fl
114
207
lead
Pb
82
119
tin
Sn
In
indium
50
73
germanium
Ge
32
28
silicon
Si
14
12
O
–
mendelevium
Md
101
169
thulium
Tm
69
209
bismuth
Bi
83
122
antimony
Sb
51
75
arsenic
As
33
–
nobelium
No
102
173
ytterbium
Yb
70
–
livermorium
Lv
116
–
polonium
Po
84
128
tellurium
Te
52
79
selenium
Se
34
32
sulfur
phosphorus
31
S
16
16
oxygen
P
15
14
nitrogen
C
carbon
49
70
gallium
Ga
31
27
aluminium
Al
13
11
boron
7
6
F
–
lawrencium
Lr
103
175
lutetium
Lu
71
–
astatine
At
85
127
iodine
I
53
80
bromine
Br
35
35.5
chlorine
Cl
17
19
fluorine
–
radon
Rn
86
131
xenon
Xe
54
84
krypton
Kr
36
40
argon
Ar
18
20
neon
Ne
10
4
9
VII
1
8
VI
He
V
helium
IV
H
5
III
hydrogen
1
The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).
actinoids
lanthanoids
–
Ra
137
133
radium
barium
Cs
caesium
Fr
lanthanoids
Ba
francium
57–71
88
56
85
55
Y
yttrium
Sr
strontium
40
48
45
39
Rb
37
rubidium
40
38
39
Ti
22
titanium
Sc
20
19
scandium
24
23
Ca
magnesium
sodium
calcium
Mg
Na
K
12
11
potassium
21
9
7
name
atomic symbol
Be
beryllium
Li
lithium
4
3
Key
atomic number
II
I
Group
The Periodic Table of Elements