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Chemistry
WAEC / WASSCE 2008
Stoichiometry, Mole Concept & Volumetric Analysis
The valence electrons in a chloride ion are [17CI]
A
2p electrons only
B
3s and 3p electrons only
C
3p and 3d electrons only
D
3p electrons only
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option B.
Source: Myschool Past Questions Archive (Record #37266)
Chemistry
WAEC / WASSCE 2008
Atomic Structure, Orbitals & Nuclear Chemistry
What is the atomic number of an element whose cation Y+ has the electronic configuration 1s22s22p6?
A
9
B
10
C
11
D
12
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option C.
Source: Myschool Past Questions Archive (Record #37267)
Chemistry
WAEC / WASSCE 2008
Atomic Structure, Orbitals & Nuclear Chemistry
Solution
Atom \(^{234} _{88} Q\) decay by alpha emission to give an atom R. The atomic number and mass number of atom R are respectively
A
86 and 230
B
87 and 234
C
88 and 233
D
90 and 238
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
\(^{234} _{88} Q \to R + ^4 _2 He\)
\(\therefore R = ^{234 - 4} _{88 - 2} R\)
= \(^{230} _{86} R\)
Source: Myschool Past Questions Archive (Record #37268)
Chemistry
WAEC / WASSCE 2008
Periodic Table & Periodicity
Which of the following statements is not true of halogens?
A
they exist in different physical states
B
they exist as diatomic molecules
C
their ionic radii decrease down the group
D
their melting and bolling points increase down the group
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option C.
Source: Myschool Past Questions Archive (Record #37269)
Chemistry
WAEC / WASSCE 2008
Periodic Table & Periodicity
Elements in the same group of the periodic table have
A
the same number of valence electrons
B
the same number of electron shells
C
different chemical behaviour
D
the same atomic size
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option A.
Source: Myschool Past Questions Archive (Record #37270)
Chemistry
WAEC / WASSCE 2008
Atomic Structure, Orbitals & Nuclear Chemistry
Consider the following elements and their electronic configurations
W: 1s22s2
X: 1s 22s22p6
Y: 1s22s22p63s2
Z: 1s22s22p63s23p2. Which of the elements belong to the same group in the periodic table?
A
W and X only
B
Y and Z only
C
W and Y only
D
W, Y and Z only
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option C.
Source: Myschool Past Questions Archive (Record #37271)
Chemistry
WAEC / WASSCE 2008
Periodic Table & Periodicity
Arrange the following elements in order of increasing electron affinity: Br2CI2
I 2
F 2
A
I 2CI2Br2F 2
B
I 2Br2CI2F 2
C
CI2 I 2Br2F 2
D
Br2CI2 I 2 F 2
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option B.
Source: Myschool Past Questions Archive (Record #37272)
Chemistry
WAEC / WASSCE 2008
Chemical Bonding & Intermolecular Forces
Water molecules are held together by
A
covalent bond
B
hydrogen bond
C
ionic forces
D
van der Waals forces
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option B.
Source: Myschool Past Questions Archive (Record #37273)
Chemistry
WAEC / WASSCE 2008
Chemical Bonding & Intermolecular Forces
Solution
The force of attraction between covalent molecules is?
A
electrostatic attraction
B
hydrogen bonding
C
ionic force
D
van der Waals forces
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
Covalent bond involves the interatomic linkage that results from the sharing of an electron pair between two atoms. The binding arises from the electrostatic attraction of their nuclei for the same electrons.
Source: Myschool Past Questions Archive (Record #37274)
Chemistry
WAEC / WASSCE 2008
Stoichiometry, Mole Concept & Volumetric Analysis
What is the mass of 6.02 x 1024 atoms of magnesium? [Mg = 24, Avogadro constant = 6.02 x 1023 atoms mol-1]
A
240g
B
24 g
C
2.4g
D
0.24g
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option A.
Source: Myschool Past Questions Archive (Record #37275)
Chemistry
WAEC / WASSCE 2008
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N = 14]
A
NH3 = 17
B
NH4CI = 53.5
C
NH4NO3 = 80
D
(NH3)2SO4 = 132
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option A.
Source: Myschool Past Questions Archive (Record #37276)
Chemistry
WAEC / WASSCE 2008
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
If 5.00cm3 of 0.20 mol dm-3Na2CO3 was diluted with distilled water to obtain 250 cm3 solution, what is the concentration of the resulting solution?
A
0.004 mol dm-3
B
0.02 mol dm-3
C
0.20mol dm-3
D
0.40mol dm-3
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
This problem can be solved by using the standard dilution formula:
C\(_1\)V\(_1\) = C\(_2\)V\(_2\)
C\(_1\) = 0.20 moldm\(^{-3}\)
V\(_1\) = 5.0 cm\(^3\)
C\(_2\) = ?
V\(_2\) = 250 cm\(^3\)
C\(_2\) = \(\frac{C_1V_1}{V_2}\)
= \(\frac{0.20 x 5.0}{250}\)
= 0.004 moldm\(^{-3}\)
Source: Myschool Past Questions Archive (Record #37278)
Chemistry
WAEC / WASSCE 2008
Kinetic Theory of Matter & Gas Laws
Consider the reaction represented by the following equation: Zn(s) + 2HCI(aq) → ZnCI2(aq) + H2(g) what volume of hydrogen gas is produced at s.t.p. when 3.25 g of zinc reacts with excess dilute HCI? [Zn = 65, Molar gas volume at s.t.p. = 22.4 dm-3]
A
1.12 dm3
B
2.24dm3
C
4.48dm3
D
8.96dm3
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option A.
Source: Myschool Past Questions Archive (Record #37279)
Chemistry
WAEC / WASSCE 2008
Kinetic Theory of Matter & Gas Laws
Which of the following gases has the lowerst rate of diffusion under the same conditions of temperature and pressure? [H = 1, O = 16, Ne = 20, CI = 35]
A
Chlorine
B
Hydrogen
C
Neon
D
Oxygen
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option A.
Source: Myschool Past Questions Archive (Record #37280)
Chemistry
WAEC / WASSCE 2008
Kinetic Theory of Matter & Gas Laws
In a fixed volume of a gas, an increase in temperature results in an increase in pressure due to an increase in the
A
number of the collisions between the gas molecules and the walls of the container
B
kinetic energy of the gas
C
number of collisions between the gas molecules
D
number of repulsion between the gas molecules
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option A.
Source: Myschool Past Questions Archive (Record #37281)