Choose the correct answer from the following multiple choice questions by making a cross (X) over your chosen letter (A, B, C, or D). 1.1.1 The correct formula for iron(III) chlorate will be (1) A. Fe 3 ClO 3 B. Fe 3 ClO 4 C. Fe(ClO 4 ) 3 D. Fe(ClO 3 ) 3 1.1.2 The correct formula for titanium (IV) oxide will be A. SnO 2 B. SnO 4 C. TiO 2 D. TiO 4
(1)
1.1.3 Lattice energy is (1) A. the amount of energy necessary to remove the outermost, highest-energy electron from an isolated neutral metal atom in the solid state. B. the amount of energy released to break a crystal lattice. C. the amount of energy needed to add the two ions together to form a crystal lattice. D. the amount of energy released when two ions come together to form a crystal lattice. 1.1.4
According to the VSEPR model the C – H bond angle in the methane molecule should be (1) A. exactly 109.5° B. less than 90° C. less than 109.5° D. exactly 120°
The O–S–O bond angle in the SO 2 molecule is 116°. The central sulphur atom in this molecule is (1) A. sp hybridized B. sp2 hybridized C. sp3 hybridized D. sp4 hybridized
1.1.5
AAICA2C/AAICC2C
1
INORGANIC CHEMISTRY II
OPPORTUNITY 2 EXAMINATION
May 2014
1.1.6 Which of the following is the weakest acid? A. HNO 3 B. HClO 3 C. H3 BO 3 D. HBrO 4+
(1)
1.1.7 Which of the following is NOT considered a covalent hydride? A. NH3 B. H2 O C. SbH3 D. NaH
(1)
1.1.8 At very high temperatures, carbon reacts with steam to produce A. carbon dioxide and hydrogen B. carbon monoxide and carbon dioxide C. methanol and hydrogen D. carbon monoxide and hydrogen
(1)
1.1.9 Which of the following hydrides can be classified as non-stoichiometric hydride? (1) A. Calcium hydride B. Palladium hydride C. Antimony trihydride D. Beryllium dihydride 1.1.10 Caustic soda or simply caustic is the common name for A. NaCl B. NaOH C. Na 2 CO 3 D. Na 2 O 2
(1)
1.1.11 The mineral trona can be represented by the following chemical formula: A. CaSO 4 .2H 2 O B. CaCO 3 .MgCO 3 C. Na 2 CO 3 .NaHCO 3 .2H2 O D. MgSO 4 .7H2 O
(1)
1.1.12 When the group IA metals reacts with excess oxygen, the following metal will produce a “normal” oxide: (1) A. Lithium AAICA2C/AAICC2C
2
INORGANIC CHEMISTRY II
OPPORTUNITY 2 EXAMINATION
May 2014
B. Sodium C. Potassium D. Rubidium 1.1.13 Which of the following does not represent an allotrope of carbon? A. Graphite B. Coal C. Diamond D. Fullerenes
(1)
1.1.14 Aluminum hydroxide has been widely used A. in tanning lather B. to absorb many dyes C. as a catalyst support D. as a drying agent
(1)
1.1.15 SiCl 4 is a Lewis acid, but CCl 4 is not. The best explanation for this is the following:(1) A. Silicon is a metalloid, while carbon is a non-metal. B. Silicon has a very strong ability to catenate, while carbon cannot. C. The Si–Cl bonds in SiCl 4 are very strongly polar, while the C–Cl bonds in CCl 4 are nonpolar. D. Silicon has d orbitals that can accommodate extra electrons, while carbon has only s and p orbitals in its valence shell. 1.1.16 A solution of hydrogen fluoride in water behaves as a weak acid. The reason for this weakness is that (1) A. extensive hydrogen bonding occurs in HF. B. F– is a hard base and competes effectively with H 2 O for the protons. C. Liquid HF is miscible with water in all proportions. D. HF has a high dipole moment and a large dielectric constant. Question 2 [15] 2.1 Write formulas for compounds with the following names: 2.1.1 Sodium oxalate.
2.1.2
(3)
Cobalt (II) phosphide
AAICA2C/AAICC2C
3
INORGANIC CHEMISTRY II
2.1.3
OPPORTUNITY 2 EXAMINATION
May 2014
Iodic acid
2.2 Give systematic names of the following compounds: 2.2.1 NaHSO 4 .2H2 O
2.2.2
Ca(CH3 COO) 2
2.2.3
BH3
(3)
2.3
Identify each of the following energy terms associated with the formation of the ionic compound LiF: (6) – 2.3.1 F2 (g) ΔH = +157.8 kJ/mol → 2F (g)
2.3.2
Li+(g) + F–(g) → LiF(s)
ΔH = –1049 kJ/mol
2.3.3
F(g) + e– → F–(g)
ΔH = –328 kJ/mol
2.3.4
Li(s) → Li(g)
ΔH = +159.4 kJ/mol
2.3.5
+ – Li(g) → Li (g) + e
ΔH = + 520.30 kJ/mol
2.3.6
Li(s) + ½F2 (g) → LiF(s)
ΔH = x
AAICA2C/AAICC2C
4
INORGANIC CHEMISTRY II
2.4
OPPORTUNITY 2 EXAMINATION
Use the data given in question 2.3 to calculate the value of x.
May 2014
(3)
Question 3 [43] 3.1
Assign formal charges to the species represented below. If there is no formal charges present for certain of these species, so indicate.
3.1.1
[ N = N = N ]–
3.1.2
[: N – N ≡ N :]–
3.2
For each of the chemical species below, (1) draw the electron-dot structure, (2) predict the molecular shape (geometry), (3) state the molecular polarity (polar or non-polar) and (4) state the hybridization of the central atom: (4) SF4
3.2.1
••
••
••
••
•• ••
AAICA2C/AAICC2C
(3)
(3)
5
INORGANIC CHEMISTRY II
OPPORTUNITY 2 EXAMINATION
May 2014
3.2.2
ICl 4 –
3.3
Using the molecular orbital diagram of nitrogen to account for the triple bond observed (8) on the Lewis diagram of N 2 .
3.3.1
How many unpaired electrons do an N 2 molecule has?
AAICA2C/AAICC2C
(4)
(1)
6
INORGANIC CHEMISTRY II
3.4
OPPORTUNITY 2 EXAMINATION
May 2014
Balance the following equation using the half-reaction method. MnO 4 -(aq) + IO 3 -(aq) → MnO 2 (s) + IO 4 - (the medium is acidic)
(6)
3.5.1
Balance the following molecular equations and write the ionic and the net ionic equations: BaBr 2 (aq) + Na 2 SO 4 (aq) → BaSO 4 (s) + NaBr(aq)
(3)
3.5.2
HC 6 H 5 CO 2 (aq) + NaOH(aq) → NaC 6 H5 CO 2 (aq) + H2 O(l)
(3)
3.5
3.6 Give the conjugate acid of each of the following: 3.6.1 OH–
AAICA2C/AAICC2C
(4)
7
INORGANIC CHEMISTRY II
OPPORTUNITY 2 EXAMINATION
May 2014
3.6.2
NH 3
3.6.3
CN–
3.6.4
HS–
3.7
Consider the acids, H 2 SO 4 and HClO 4 . Which acid will be the stronger acid? Explain your answer. (4)
Question 4 [6] 4.1
Explain why most binary compounds of hydrogen are covalent rather than ionic. (3)
4.2
How would you compare the sizes of the hydrogen ion, H+, and that of a hydride ion, H–, to that of a helium, He, atom. Elaborate your answers. (3)
AAICA2C/AAICC2C
8
INORGANIC CHEMISTRY II
OPPORTUNITY 2 EXAMINATION
May 2014
Question 5 [9] 5.1
Why does Rb (rubidium) react explosively with water whereas Li (lithium) reacts gently? (2)
5.2
Which Group 1A element is used for fertilisers?
(1)
5.3
Give the balanced chemical reaction where Na 2 O 2 reacts with water.
(2)
5.4
How is Mg produced? Give the chemical reaction.
(3)
5.5
What is the trivial name for magnesium hydroxide (Mg(OH) 2 ).
(1)
Question 6 [10] 6.1
Name one use for borax.
(1)
6.2
What is used as the reducing agent in the Hall–Héroult process?
(1)
6.3
Name two uses for the Thermite reaction?
(2)
6.4
Is the Thermite reaction exothermic or endothermic?
(1)
AAICA2C/AAICC2C
9
INORGANIC CHEMISTRY II
OPPORTUNITY 2 EXAMINATION
May 2014
6.5
When is a compound amphoteric?
(2)
6.6
Name one use for aluminium carbide.
(1)
6.7
What is the difference between aluminium and alumina?
(2)
Question 7 [7] 7.1
Which commercial application is the most lead being used for?
(1)
7.2
Why did the use of lead decrease?
(1)
7.3
Name the three types of carbides.
(3)
7.4
Give the chemical equation for when Al 4 C 3 reacts with water.
(2)
Question 8 [7] 8.1 Name two oxides of nitrogen.
AAICA2C/AAICC2C
(2)
10
INORGANIC CHEMISTRY II
OPPORTUNITY 2 EXAMINATION
May 2014
8.2
How is the presence of large amounts of NO in the atmosphere impacting on the environment? (3)
8.3
Explain why NH 3 is more polar than NCl 3 .
(2)
Question 9 [4] 9.1 State one important use of oxygen.
(1)
9.2
Write a chemical equation for the preparation of ozone in the atmosphere.
(1)
9.3
Give two substances that cause decomposition of hydrogen peroxide.
(2)
Question 10 [5] 10.1
Write a balanced equation for the electrolysis of dilute sodium chloride solution. (2)
