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Chemistry
WAEC / WASSCE 2007
Metals, Transition Elements & Extraction
A transition metal would be expected to
A
from oxides with different formulae
B
have strong oxidizing ability
C
have low density
D
have an atomic structure with an incomplete outermost shell
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 #37136)
Chemistry
WAEC / WASSCE 2007
Periodic Table & Periodicity
Which of the following properties of atoms generally increases down a group in the periodic table?
A
Electron affinity
B
Electronegativity
C
Ionic radius
D
lonization energy
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 #37137)
Chemistry
WAEC / WASSCE 2007
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following statements about sodium is not true?
A
Na+ is smaller in size than Na
B
Na is smaller in size than Na+
C
Na+ has fewer electrons than Na
D
The effective nuclear charge in Na+ is greater than in Na
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 #37138)
Chemistry
WAEC / WASSCE 2007
Chemical Bonding & Intermolecular Forces
If the difference between the electronegativities of two elements is large, the type of bond that can be formed between them is
A
covalent
B
dative
C
ionic
D
metallic
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 #37139)
Chemistry
WAEC / WASSCE 2007
Chemical Bonding & Intermolecular Forces
Which of the following compounds has hydrogen bonds between its molecules?
A
HF
B
HBr
C
HCI
D
HI.
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 #37144)
Chemistry
WAEC / WASSCE 2007
Chemical Bonding & Intermolecular Forces
Which of the following species does not contain a co-ordinate bond?
A
AI2CI6
B
CCI4
C
H3O+
D
NH + 4
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 #37145)
Chemistry
WAEC / WASSCE 2007
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
14.8 g of a salt (z)dissolved in 250 cm3 of distilled water gives a concentration of 0.80 mol dm-3. Calculate the molar mass of the salt (z).
A
13.5 g mol-1
B
18.5 g mol-1
C
47.4 g mol-1
D
74.0 g mol-1
medium Difficulty
Verified Correct Answer: Option D
Chemical Principles & Mechanism
250cm3 of distilled water contains 14.8g of salt(z)
1cm3 of distilled water will contain \(\frac{14.8 x 1}{250}\) of salt (z)
:. 1000cm3 of distilled water will contain \(\frac{14.8 x 1 x 1000}{250}\) = 59.2g/dm33 = \(\frac{concentration in g/dm3}{molar mass}
0.80 = \(\frac{59.2}{molar mass}\)
molar mass = \(\frac{59.2}{0.80}\) = 74.0 g/mol
Source: Myschool Past Questions Archive (Record #37152)
Chemistry
WAEC / WASSCE 2007
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
How many atoms are there in one mole of hydrogen gas? [Avogadro's constant = 6.02 x 1023mol-1]
A
1.2 x 10 23
B
6.0 x 10 23
C
1.2 x10 24
D
6.0 x 10 24
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
One mole of hydrogen gas has 6.02 x 1023 molecules, and one molecule of hydrogen gas contains 2 atoms of hydrogen
therefore, one mole of hydrogen gas will contain 2 x 6.02 x10^23 atoms
= 1.2 x 10^24 hydrogen atoms
Source: Myschool Past Questions Archive (Record #37159)
Chemistry
WAEC / WASSCE 2007
Stoichiometry, Mole Concept & Volumetric Analysis
What is the IUPAC name of the compound represented by the molecular formula NaCIO4?
A
Sodium tetraoxochlorate (l)
B
Sodium tetraoxochlorate (IV)
C
Sodium tetraoxochlorate (VI)
D
Sodium tetraoxochlorate(VII)
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 #37179)
Chemistry
WAEC / WASSCE 2007
Periodic Table & Periodicity
When air is successively passed through sodium hydroxide solution, alkaline pyrogallol and then concentrated tetraoxosulphate (VI) acid, its remaining components are
A
oxygen and water vapour
B
oxygen and nitrogen
C
carbon (IV) acid and noble gases
D
nitrogen and noble gases
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 #37183)
Chemistry
WAEC / WASSCE 2007
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following gases is light than air?
A
CO2
B
SO2
C
HCI
D
NH3
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 #37186)
Chemistry
WAEC / WASSCE 2007
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following statements is true of the molecules of a gas under ideal conditions? The molecules
A
move at random
B
undergo inelastic collisions
C
attract each other
D
occupy a large volume
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 #37188)
Chemistry
WAEC / WASSCE 2007
Chemical Energetics & Thermochemistry
Solution
In which of the following compound (s) will heat be absorbed on adding water?
l. KNO\(_3\) II. Concentrated H\(_2\)SO\(_4\) III. NH\(_4\)CI
A
I only
B
lll only
C
l and lll only
D
ll and lll only
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
KNO\(_3\) and NH\(_4\)Cl both undergo endothermic.
Source: Myschool Past Questions Archive (Record #37189)
Chemistry
WAEC / WASSCE 2007
Oxidation, Reduction & Redox Reactions
Consider the reaction represented by the equation: Ca(OH)2(aq) + CO 2(g) → CaCO3(s) + H 2O(l)
in the reaction above, CO 2 acts as
A
an acidic oxide
B
an oxidizing agent
C
a basic oxide
D
a dehydrating agent
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 #37193)
Chemistry
WAEC / WASSCE 2007
Acids, Bases, pH & Salts
Which of the following compounds is a basic salt?
A
Mg(NO3)2
B
(NH4)2SO4
C
K4Fe(CN)6
D
Zn(OH)CI
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 #37194)