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Chemistry
WAEC / WASSCE 2015
Matter & Separation Techniques
The following transition metal ions would be coloured in aqueous solution except________?
A
Cr3+
B
Fe3+
C
Mn3+
D
Sc3+
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 #45745)
Chemistry
WAEC / WASSCE 2015
Matter & Separation Techniques
The gas given off when ethanol reacts with sodium is
A
Carbon(IV)oxide
B
Hydrogen
C
Methane
D
Oxygen
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 #45746)
Chemistry
WAEC / WASSCE 2015
Matter & Separation Techniques
Which of the following halogens is solid at room temperature?
A
Bromine
B
Chlorine
C
Flourine
D
Iodine
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 #45747)
Chemistry
WAEC / WASSCE 2015
Matter & Separation Techniques
The alkaline earth metals have similar chemical properties because________?
A
They are in the same period
B
Their salts are colourless
C
They have the same number of valence electrons
D
They are very reactive
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 #45748)
Chemistry
WAEC / WASSCE 2015
Atomic Structure and Periodic Table
The number of unpaired electrons in an atom of an element 8Q is _______?
A
2
B
4
C
6
D
8
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 #45749)
Chemistry
WAEC / WASSCE 2015
Atomic Structure and Periodic Table
The bond formed when ammonia reacts with hydrogen ion to form ammonium ion is
A
Covalent
B
Dative
C
Hydrogen bond
D
Ionic
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 #45750)
Chemistry
WAEC / WASSCE 2015
Atomic Structure and Periodic Table
Solution
To which group and period respectively does an element with 15 electrons belong?
A
3 and 3
B
3 and 5
C
5 and 3
D
5 and 5
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
An element with 15 electrons is Phosphorus (P), which belongs to Group 5 and Period 3, as its electron configuration ends in, showing 5 valence electrons in the third shell.
Source: Myschool Past Questions Archive (Record #45751)
Chemistry
WAEC / WASSCE 2015
Acids, Bases, and Salts
The shape of a graphite crystal is
A
Tetrahedral
B
Pyramidal
C
Octahedral
D
Hexagonal
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 #45752)
Chemistry
WAEC / WASSCE 2015
Atomic Structure and Periodic Table
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
Matter & Separation Techniques
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
Acids, Bases, and Salts
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
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
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
Matter & Separation Techniques
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
Matter & Separation Techniques
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)