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Chemistry
WAEC / WASSCE 2014
Chemical Bonding & Intermolecular Forces
The shape of CH4 is
A
linear
B
planar
C
pyramidal
D
tetrahedral
medium Difficulty
Verified Correct Answer: Option D
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option D.
Source: Myschool Past Questions Archive (Record #37820)
Chemistry
WAEC / WASSCE 2014
Chemical Bonding & Intermolecular Forces
Solution
The crystal layers in graphite are held together by
A
covalent bond
B
electrostatic forces
C
ionic bond
D
van der Waal's forces
medium Difficulty
Verified Correct Answer: Option D
Chemical Principles & Mechanism
The atoms in a given layer are held together by strong covalent linkages, but the forces between the layers are the weak van der waals forces
Source: Myschool Past Questions Archive (Record #37821)
Chemistry
WAEC / WASSCE 2014
Chemical Bonding & Intermolecular Forces
Hydrogen bonds are formed between molecules containing a hydrogen atom bonded to a
A
strongly electronegative atom
B
non-polar species
C
diatomic element
D
complex ion
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 #37822)
Chemistry
WAEC / WASSCE 2014
Periodic Table & Periodicity
The two elements 11X and 19Y are in the same group because they have the same
A
valence electrons
B
ionization energy
C
number of shell
D
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 #37823)
Chemistry
WAEC / WASSCE 2014
Periodic Table & Periodicity
Which of the following arrangements is in decreasing order of atomic radius?
A
Li>Be>C>
B
Li>B>Be>C
C
Li>Be>B>C
D
C>B>Be>Li
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 #37824)
Chemistry
WAEC / WASSCE 2014
Atomic Structure, Orbitals & Nuclear Chemistry
Which of the following processes is used in food preservation in an industry?
A
Carbon dating
B
Ieeadiation of gamma rays
C
Nuclear fission
D
Nuclear fusion
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 #37825)
Chemistry
WAEC / WASSCE 2014
Atomic Structure, Orbitals & Nuclear Chemistry
Solution
The relative atomic mass of chlorine is not a whole number because
A
it is the weighted average mass of all its various isotopes
B
it is the average mass of all the isotopes of the element
C
the element has strong oxidizing ability
D
the atom contains a higher number of neutrons than protons
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
The relative atomic mass of an element is calculated as a weighted average of the masses of its naturally occurring isotopes. Because the isotopes of chlorine (\(^{35}\)Cl and \(^{37}\)Cl) occur in different proportions (natural abundance), their masses are averaged according to those percentages. The resulting value (approximately 35.5) is not a whole number because it reflects this proportional distribution rather than the mass of a single atom.
Source: Myschool Past Questions Archive (Record #37829)
Chemistry
WAEC / WASSCE 2014
Stoichiometry, Mole Concept & Volumetric Analysis
NH4- is formed from NH3 and H- by
A
covalent bonding
B
dative bonding
C
hydrogen bonding
D
ionic bonding
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 #37830)
Chemistry
WAEC / WASSCE 2014
Chemical Bonding & Intermolecular Forces
How many lone pair (s) of electrons is present in HF?
A
o
B
1
C
2
D
3
medium Difficulty
Verified Correct Answer: Option D
Chemical Principles & Mechanism
No expanded working has been attached for this question yet. The verified answer is Option D.
Source: Myschool Past Questions Archive (Record #37831)
Chemistry
WAEC / WASSCE 2014
Acids, Bases, pH & Salts
An aqueous solution of Na2CO3 is
A
acidic
B
alkaline
C
amphoteric
D
neutral
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 #37832)
Chemistry
WAEC / WASSCE 2014
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
A gaseous mixture contains 0,256 g of hydrogen and 2.00 g of oxygen. The mole ration of hydrogen to oxygen in the mixture is (H=1.00; O=16,0)
A
1:1
B
2:1
C
1:4
D
8:1
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
Mole = \(\frac{Mass}{Molar Mas}\) : \(\frac{Mass}{Molar Mass}\)
\(\frac{0.256}{2}\) : \(\frac{2}{32}
0. 128 : 0.0625
\(\frac{0.128}{0.0625}\) : \(\frac{0.0625}{0.0625}\)
2 : 1
Source: Myschool Past Questions Archive (Record #37839)
Chemistry
WAEC / WASSCE 2014
Oxidation, Reduction & Redox Reactions
Solution
The oxidation number of sulphur in Fe2(SO4)3 is
A
+2.
B
+3
C
+4.
D
+6.
medium Difficulty
Verified Correct Answer: Option D
Chemical Principles & Mechanism
Fe2(SO4)3 = 0
(+3 x 2) 9 3x + (-2 x 4 x 3) = 0
+6 + 3x -24 = 0
+3x - 18 = 0
3 x = 18
x = 18/3 = +6
Source: Myschool Past Questions Archive (Record #37840)
Chemistry
WAEC / WASSCE 2014
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
If 0.20 mol dm-3 NaOH(aq) was evaporated to yield 5.0g of solid NaOH, calculate the volume of NaOH (aq) used. (Na = 23.0,O = 16:0; H = 1.00)
A
600cm-3
B
625cm3
C
10003
D
1600 cm 3
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
Mole = 5/40 = 0.125 mole
:. 0.2 mole NaOH dissolved in 1000 cm3
0.125 mole NaOH dissolved in xcm3
xcm3 = \(\frac{0.215 x 1000}{0.2}\)
= 625cm3
Source: Myschool Past Questions Archive (Record #37847)
Chemistry
WAEC / WASSCE 2014
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
The mass of 800cm3 of gas Q at s.t.p. is 1.0g. What is the molar mass of Q? [Avogadros constant = 22.4dm3 mol-1`]
A
18.0 gmol-1
B
22,4gmol-1
C
28.0gmol-1
D
36.0 gmol-1
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
Imole Q occupies 22400 cm3
x mole occupies 800 cm3
x = \(\frac{800 x 1}{22400}\)
= 0.036mol
Molar mass = Mass \div Mole
= 1 \div 0.036
Molar mass ≈ 28 g/mol
Source: Myschool Past Questions Archive (Record #37848)
Chemistry
WAEC / WASSCE 2014
Reaction Rates & Chemical Equilibrium
Which of the following statements about a chemical system in equilibrium is correct/ The
A
reaction is irreversible
B
reaction goes to completion
C
equilibrium is re-established when a stress is applied
D
equilibrium position is affected by catalyst
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 #37849)