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WorksheetsChapter 7 to Chapter 9
Total questions: 20
Worksheet time: 5hrs 0mins
The standard enthalpies of formation of FeO and Fe2O3 are -272 and -826 kJ mol-1 respectively.
Which statement is not true about the oxides?
Both FeO and Fe2O3 are more stable than their elements.
Fe2O3 is more stable than FeO.
Fe reacts exothermically with O2 to form the oxides
The enthalpy of formation of Fe2O3 is given by
2 FeO (s) + ½ O2 (g) →Fe2O3 (s)
Which of the following species has the highest ionisation energy?
Al2+
Mg2+
Zn+
Fe2+
Calculate the heat change for the following reaction:
FeO (s) + Fe2O3 (s) --> Fe3O4 (s)
Given the following heat of formation:
FeO: -272 kJmol-1
Fe2O3: -826 kJmol-1
Fe3O4: -1118 kJmol-1
-44
-20
+20
+44
A current of 4.5 A is passed through sodium hydroxide solution for 120 minutes using graphite electrodes. What is the volume of the gas collected at the anode at s.t.p.?
[Faraday's constant = 96500 Cmol-1, 1 mol of gas occupies 22.4 dm3 at s.t.p.]
0.031 dm3
1.9 dm3
3.8 dm3
7.7 dm3
Which compound has the highest lattice energy?
Na2O
NaCl
MgO
MgCl2
The Daniell cell is shown below:
Which of the following is incorrect when a current is drawn from the cell?
Electrons flow from zinc to copper through the external circuit.
Copper is deposited in the copper half-cell.
Sulphate ions migrate through the salt bridge from the zinc half-cell to copper half-cell.
Cathode forms the cathode of the cell.
Which of the following has the largest size?
Na+
Al3+
S2-
Cl-
Atoms of Period 3 elements are larger than their corresponding counterparts in Period 2 because
Period 3 elements are more metallic.
Period 3 elements have one extra electronic shell.
Period 3 elements are more electronegative.
Period 3 elements have higher density.
Heat is absorbed when NaCl dissolves in water. Which enthalpies are involved in the solubility of this compound?
I) Hydration energy
II) Electron affinity
III) Ionisation energy
IV) Lattice energy
I and II
I and IV
II and III
III and IV
The half-cell equation and the standard reduction potential for X and Y are shown below.
What is the e.m.f. of the cell constructed from the two half cells?
-1.14V
-0.46V
+0.46V
+1.26V
The Nernst equation is written as
For the reaction Mg (s) + 2H+ (aq) --> Mg2+ (aq) + H2 (g), Q may be expressed as
Which statement explains why graphite powder is spread onto plastic material first in plastic electroplating process?
Graphite is an electric conductor.
Plastic becomes more resistant to heat.
Plastic electroplating process is accelerated.
Graphite can form chemical bond with plastic.
The first ionisation energies of five elements in Period 2 of the Periodic Table is shown in the graph below.
Which statement explains the difference in the first ionisation energies between beryllium and boron?
Boron atom has more valence electrons.
Boron atom has a greater shielding effect.
Beryllium atom has a more stable electronic configuration.
The 2p electron in boron atom is at a higher energy level than the 2s electron in beryllium atom.
Elements X, Y and Z are located in Period 3 of the Periodic Table. The reactivity of these elements towards oxygen is shown in the table.
The arrangement of the elements according to the ascending order of their proton number is
X, Y, Z
x, Z, Y
Z, X, Y
Z, Y, X
Which oxide will produce 1.0 mol dm-3 aqueous solution with the lowest pH value?
Na2O
MgO
P2O5
SO3
The radii of four ions are as follows:
Which ion has the largest hydration energy?
U+
V-
W2+
X2+
The diagram below illustrates the energy cycle for the formation of potassium chloride.
Which of the following enthalpy changes is correctly represented?
H1 Enthalpy of vaporisation
H2 Enthalpy of formation
H3 Enthalpy of hydration
H4 Enthalpy of solution
When solution of a salt of metal X was electrolysed, metal X and a diatomic gas Y were produced in molar ratio of 4:1 at the cathode and anode respectively. If the same quantity of electricity was passed through a concentrated solution of sodium chloride, a gas Z was evolved at the anode. The molar ratio of X : Y : Z is
4:1:1
4:1:2
4:1:3
4:1:4
4:1:5
A diaphragm cell is used in the manufacturing of sodium hydroxide by the electrolysis of brine. Which statement is true of the cell?
The diaphragm is made of asbestos
Na+ ions migrate to anode through the diaphragm
Cl2 is produced at the cathode
NaOH is produced at the anode
The standard redox potentials for some half-cells are shown below.
Under standard conditions, a colour change is observed when
I) aqueous solution of I- is added to aqueous solution of Fe3+
II) aqueous solution of Br- is added to aqueous solution of Fe3+
III) aqueous solution of CI- is added to aqueous solution of Fe3+
I only
I and II only
II and III only
I, II and III
