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Chemistry
UTME / JAMB 2013
Stoichiometry & Mole Concept
Solution
The presence of an impurity in substance will cause the melting point to
A
be zero
B
reduce
C
increase
D
be stable
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
Impurities disrupt the repeating pattern of forces that holds the solid together. So a smaller amount of energy is required to melt the part of the solid surrounding the impurity. If less energy is required, then this explains the melting point depression (lowering) observed from impure solids. The more impure the solid is, the more the structure is disrupted and the greater the variation in intermolecular forces in different areas of the solid.
Source: Myschool Past Questions Archive (Record #27428)
Chemistry
UTME / JAMB 2013
Matter & Separation Techniques
What volume of carbon (ll) oxide is produced by reacting excess carbon with 10 dm3 of oxygen?
A
5 dm 3
B
20 dm 3
C
15 dm 3
D
10 dm 3
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 #27429)
Chemistry
UTME / JAMB 2013
Atomic Structure and Periodic Table
The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is
A
carbon-14
B
phosphorus-32
C
cobalt-60
D
iodine-131
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 #27431)
Chemistry
UTME / JAMB 2013
Stoichiometry & Mole Concept
The shape of the carbon (lV) oxide molecule is
A
pyramidal
B
linear
C
angular
D
tetrahedral
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 #27432)
Chemistry
UTME / JAMB 2013
Atomic Structure and Periodic Table
Solution
Which of the following molecules is held together by hydrogen bond?
A
CH4
B
HBr
C
H2SO4
D
HF
medium Difficulty
Verified Correct Answer: Option D
Chemical Principles & Mechanism
HF is held by hydrogen bonding.
Source: Myschool Past Questions Archive (Record #27433)
Chemistry
UTME / JAMB 2013
Atomic Structure and Periodic Table
The bond formed between two elements with electron configurations 1s2 2s2 2p6 3s2 and 1s2 2s2 2p4 is
A
metallic
B
covalent
C
dative
D
ionic
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 #27434)
Chemistry
UTME / JAMB 2013
Matter & Separation Techniques
The constituent of air that acts as a diluent is
A
nitrogen
B
carbon (IV) oxide
C
noble gases
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 #27435)
Chemistry
UTME / JAMB 2013
Matter & Separation Techniques
Steam changes the colour of anhydrous cobalt (ll) chloride from
A
white to red
B
blue to white
C
blue to pink
D
white to blue
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 #27436)
Chemistry
UTME / JAMB 2013
Matter & Separation Techniques
An example of a hygroscopic substance is
A
CuO (S).
B
MgCL2(S).
C
CaCL2(S).
D
NaOH(S).
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 #27437)
Chemistry
UTME / JAMB 2013
Acids, Bases, and Salts
Solution
The solvent used for removing grease stain is
A
turpentine
B
ammonia solution
C
ethanol
D
solution of borax in water
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
Ammonia solution (also known as aqueous ammonia or ammonium hydroxide) is frequently used in laundries and household cleaners as a solvent for removing grease and oil stains. It is effective because it reacts with fatty acids in grease to form soluble soaps (a process called saponification) or helps emulsify the oils so they can be washed away with water.
Source: Myschool Past Questions Archive (Record #27439)
Chemistry
UTME / JAMB 2013
Matter & Separation Techniques
In a water body, too much sewage leads to
A
a decrease in the temperature of the water which cause in death of aquatic animals
B
an increase in the number of aquatic animals in the water
C
an increase in the bacterial population which reduces the level of oxygen in the water
D
a decrease in the bacterial population which increases the level of oxygen in the water
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 #27440)
Chemistry
UTME / JAMB 2013
Matter & Separation Techniques
Solution
10.0 dm3 of water was added to 2.0 mol dm-3 of 2.5dm3 solution of HCl. What is the concentration of the final solution in mol dm-3?
A
0.4
B
8.0
C
2.0
D
0.5
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
C1V1 = C2V2
C2 = \(\frac{C_1V_1}{V_2}\)
= \(\frac{2.0 \times 2.5}{12.5}\)
= 0.4mol/dm-3
Source: Myschool Past Questions Archive (Record #27441)
Chemistry
UTME / JAMB 2013
Acids, Bases, and Salts
Three drops of a 1.0 mol dm-3 solution of HCl was added to 20 cm3 of a solution of pH6.4. The pH of the resulting solution will be
A
close to that of pure water
B
less than 6.4
C
greater than 6.4
D
unaltered
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 #27442)
Chemistry
UTME / JAMB 2013
Acids, Bases, and Salts
Which of the following substances is not a salt?
A
Aluminium oxide
B
Sodium hydrogentrioxosulphate (V)
C
Sodium trioxocarbonate (V)
D
Zinc chloride
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 #27443)
Chemistry
UTME / JAMB 2013
Acids, Bases, and Salts
An insoluble salt can be prepared by
A
the reaction of trioxocarbonate (V) with an acid
B
double decomposition
C
the action of dilute acid on an insoluble base
D
the reaction of metals with an acid
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 #27444)