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Chemistry
WAEC / WASSCE 2015
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following oxides is ionic?
A
P4O10
B
MgO
C
Al2O3
D
SO2
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 #45753)
Chemistry
WAEC / WASSCE 2015
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
Which of the following substances when boiled with aqueous solution of sodium hydroxide would be hydrolyzed?
i. Protein ii. Fat iii. Polythene
A
i
B
ii
C
i and ii
D
ii and iii
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 #45755)
Chemistry
WAEC / WASSCE 2015
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following trioxonitrate(V) salts would decompose on heating to form a metal?
A
Cu(NO3)2
B
AgNO3
C
Pb(NO3)2
D
KNO3
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 #45756)
Chemistry
WAEC / WASSCE 2015
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
Consider the following reaction equation:
C2H4(g) + 3O2(g) \(\to\) 2CO2(g) + 2H2O(g)
The volume of CO2(g) produced at s.t.p when 0.05 moles of C2H4(g) was burnt in O2(g) is
[Molar Volume of gas = 22.4dm3
A
1.12dm3
B
2.24dm3
C
3.72dm3
D
4.48dm3
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
\(\frac{\text{volume}}{\text{molar volume}}\) = 0.05
1 mole of ethane produces 2 moles of carbon(iv)oxide
∴ 0.05 mole of ethane will produce x moles of carbon(iv)oxide
= \(\frac{\text{volume}}{22.4}\) = 0.05 X 2 X 22.4 = 2.24dm\(_3\)
Source: Myschool Past Questions Archive (Record #45758)
Chemistry
WAEC / WASSCE 2015
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
The number of oxygen molecules present in 16.0g of the gas is ______?
[Avogadro's number = 6.02 x 1023]
A
6.02 x 1022
B
6.02 x 1023
C
3.01 x 1023
D
1.51 x 1023
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
1 mole = Molar mass of gas = Avogadros number
32g of O2 = 6.02 x 1023
16g of O2 = x
x = \(\frac{16 \times 6.02 \times 10^23}{32}\) = 3.01 x 1023
Source: Myschool Past Questions Archive (Record #45759)
Chemistry
WAEC / WASSCE 2015
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
Consider the following reaction equation:
SO42-(aq) + 2H+(aq) + ye- \(\to\) SO42-(aq) + H2O(1).
The value of y in the equation is
A
2
B
3
C
4
D
6
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
from the reaction, the total charge on the left side = The total charge on the right side
-2 + 2 + y = -2 : y = -2 : y = 2
Source: Myschool Past Questions Archive (Record #45760)
Chemistry
WAEC / WASSCE 2015
Particulate Nature of Matter, Laws & Formulae
The general gas equation was deprived from______?
A
Boyle's and Gay Lussac's laws
B
Boyle's and Graham's laws
C
Boyle's and Charles' laws
D
Dalton's atomic theory
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 #45764)
Chemistry
WAEC / WASSCE 2015
Stoichiometry, Mole Concept & Volumetric Analysis
The vapour pressure of a liquid depends on:
I. Temperature II. rate of condensation III. Cohesive forces holding the particles together.
A
I
B
I and II
C
I and III
D
II and III
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 #45769)
Chemistry
WAEC / WASSCE 2015
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following gases will diffuse most rapidly?
[H = 1.00, C = 12.0, O = 16.0, S = 32.0, Cl = 35.5]
A
Cl2
B
SO2
C
CH4
D
C2H6
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 #45771)
Chemistry
WAEC / WASSCE 2015
Chemical Energetics & Thermochemistry
Solution
When a reaction is endothermic,
A
Enthalpy change, \(\Delta\)H is negative
B
Heat content of a product is less than the heat content of a reactant
C
Heat content of reactants is less than the heat content of product
D
The reaction is non-spontaneous
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
An endothermic reaction is any chemical reaction that absorbs heat from its environment. The absorbed energy provides the activation energy for the reaction to occur.
Source: Myschool Past Questions Archive (Record #45773)
Chemistry
WAEC / WASSCE 2015
Acids, Bases, pH & Salts
Solution
An example of an acid salt is
A
CH3COOONa
B
Mg(OH)Cl
C
NaHSO4
D
(NH4)2SO4
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
Acidic Salt: A normal salt which is formed by the neutralization of a strong acid and weak base is called acidic salt
Source: Myschool Past Questions Archive (Record #45779)
Chemistry
WAEC / WASSCE 2015
Electrolysis & Electrochemical Cells
Solution
Which of the following oxides can be reduced by hydrogen?
A
Aluminium oxide
B
Magnesium oxide
C
Sodium oxide
D
Silver oxide
medium Difficulty
Verified Correct Answer: Option D
Chemical Principles & Mechanism
Considering the electrochemical series, we can say that hydrogen can reduce only oxides of copper, mercury, silver, and gold as these metals are less reactive than hydrogen. The reduction of oxides of tin, iron, zinc, magnesium, calcium, and potassium is not possible by hydrogen as these metals are more reactive than hydrogen
Source: Myschool Past Questions Archive (Record #45780)
Chemistry
WAEC / WASSCE 2015
Water, Solutions & Solubility
Solubility is practically applied in
A
Fractional distillation
B
The determination of pH
C
The determination of saturation in hydrocarbons
D
Solvent extraction
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 #45818)
Chemistry
WAEC / WASSCE 2015
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following compounds is the least soluble in water?
A
CaCl2
B
CaSO4
C
NaCl
D
Na2SO4
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 #45819)
Chemistry
WAEC / WASSCE 2015
Chemical Bonding & Intermolecular Forces
A substance which dissolves readily in organic solvent would
A
Be a covalent compound
B
Have strong electrostatic forces of attraction
C
have a high melting point
D
Conduct electricity in molten state
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 #45821)