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Chemistry
UTME / JAMB 1986
Acids, Bases, pH & Salts
In the course of an experiment, two gases X and Y were produced. X turned wet lead ethanoate to black and Y bleached moist litmus paper. What are the element(s) in each of the gases X and Y respectively?
A
H and S;Cl
B
H and O;Cl
C
H and S;C and O
D
H and Cl;S and O
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 #14162)
Chemistry
UTME / JAMB 1986
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
Which of the following metals does NOT form a stable trioxocarbonate (IV)?
A
Fe
B
Al
C
Zn
D
Pb
E
none of the options is correct
medium Difficulty
Verified Correct Answer: Option E
Chemical Principles & Mechanism
Iron (Fe) does not form a stable trioxocarbonate (IV) (also known as carbonate) in the sense of a stable, isolable compound. Carbonate ions (CO\(_3\) \(^{2-}\)) are typically found in compounds with other cations, not with iron in a stable, isolated form.
Aluminum (Al) does not form a stable trioxocarbonate (IV) (Al\(_2\)(CO\(_3\))\(_3\)) under normal conditions; it is an unstable compound, and when sodium trioxocarbonate (IV) is added to an aluminum salt solution, aluminum hydroxide precipitates and carbon dioxide is liberated.
Zinc (Zn) does form a stable trioxocarbonate (IV), which is commonly known as zinc carbonate (ZnCO\(_3\)). Zinc carbonate can be prepared by mixing a solution of a zinc salt (like zinc sulfate) with a solution of sodium carbonate.
Lead (Pb) does not typically form a stable trioxocarbonate (IV) (PbCO\(_3\)) under normal conditions, and it is not known to form a stable trioxocarbonate (IV).
Source: Myschool Past Questions Archive (Record #14163)
Chemistry
UTME / JAMB 1986
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following sulphides is insoluble in dilute HCl?
A
Na2S
B
ZnS
C
CuS
D
FeS
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 #14164)
Chemistry
UTME / JAMB 1986
Stoichiometry, Mole Concept & Volumetric Analysis
When chlorine is passed into water and subsequently exposed to sunlight, the gas evolved is?
A
HCl
B
HOCl
C
O2
D
Cl2O
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 #14165)
Chemistry
UTME / JAMB 1986
Water, Solutions & Solubility
A substance Z reacts with NaOH to give salt and water only. When Z is treated with dilute HCl, a gas is evolved which gives a yellow suspension on passing into concentrated H2SO4. Substance Z is?
A
NaHS
B
Na2SO3
C
Na2S
D
NaHSO3
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 #14166)
Chemistry
UTME / JAMB 1986
Acids, Bases, pH & Salts
Ammonia gas is normally dried with?
A
concentrated sulphuric acid
B
quicklime
C
anhydrous calcium chloride
D
magnesium sulphate
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 #14167)
Chemistry
UTME / JAMB 1986
Stoichiometry, Mole Concept & Volumetric Analysis
What are the values of x, y and z respectively in the equation: xCu + yHNO3 → xCu(NO3)2 + 4H2O + zNO?
A
4: 1: 2
B
3:8:2
C
2:8:3
D
8:3:2
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 #14168)
Chemistry
UTME / JAMB 1986
Nature of Matter & Separation Techniques
The iron (III) oxide impurity in bauxite can be removed by?
A
Fractional crystallization in acid solution
B
dissolution in sodium hydroxide and filtration
C
extraction with concentrated ammonia and reprecipitation
D
electroysis of molten mixture
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 #14169)
Chemistry
UTME / JAMB 1986
Acids, Bases, pH & Salts
Solution
Which of the following does NOT contain aluminium as component?
A
Over-head cables
B
Duralumin
C
Container for caustic soda
D
Container for nitric acid
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
Sodium Hydroxide reacts with metals, such as Aluminium, Lead, Tin and Zinc, to form flammable and explosive Hydrogen gas. Hence, Aluminium cannot be used as a component for storing caustic soda.
Source: Myschool Past Questions Archive (Record #14171)
Chemistry
UTME / JAMB 1986
Acids, Bases, pH & Salts
Solution
A white solid suspected to be lead trioxonitrate (V) zinc trioxocarbonate (IV) or calcium trioxocabonate (IV) was heated strongly. Its residue which was yellow when hot and white when cold is?
A
lead (II) oxide
B
calcium oxide
C
zinc oxide
D
lead nitrate
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
Zinc oxide is an amphoteric oxide, meaning it can react with both acids and bases. It's typically white at room temperature, but when heated, it loses oxygen and turns yellow. This color change is reversible, and the oxide reverts to white upon cooling.
The amphoteric oxide that is yellow when hot and white when cold is zinc oxide (ZnO).
Source: Myschool Past Questions Archive (Record #14172)
Chemistry
UTME / JAMB 1986
Metals, Transition Elements & Extraction
Which of the following compounds would give lilac flame coloration and a white precipitate with acidified barium chloride solution?
A
KCI
B
NaNO3
C
K2SO4
D
CaSO4
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 #14173)
Chemistry
UTME / JAMB 1986
Electrolysis & Electrochemical Cells
How will a metal X, which reacts explosively with air and with dilute acids be best extracted from its ores?
A
Electrolysis of solution of its salts
B
Decomposition of its oxides
C
Displacement from solution by an alkali metal
D
Electroiysis of fused salt
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 #14174)
Chemistry
UTME / JAMB 1986
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
Which of the following is NOT correct test for the named organic compound in each case?
A
Butanoic acid solution gives effervescence with Na2CO3 solution
B
Glucose when reacted with Na2CrO4 at 0°C will show immediate discharge of colour
C
When but-2-ene is reacted with dilute solution of KMnO4 the purple colour of KMnO is discharged readily even room temperature
D
When butan-2-ol is boiled with butanoic acid with a drop of concentrated H2SO4 a sweet smelling liquid is produced
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 #14175)
Chemistry
UTME / JAMB 1986
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
Solution
What reaction takes place when palm-oil is added to potash and foam are observed?
A
Neutralization
B
Saponification
C
Esterification
D
Salting-out
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
The reaction of palm oil with potash is known as saponification reaction, palm oil serves as the organic acid(palmitic acid) while potash( conc. KOH) serves as the base leading to the formation of soap(the presence of bubbles indicate the formation of soap)
Source: Myschool Past Questions Archive (Record #14179)
Chemistry
UTME / JAMB 1986
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
When ethanol is heated with excess concentrated sulphuric acid, the ethanol is?
A
oxidized to ethene
B
polymerized to polyethene
C
dehydrated to ethene
D
dehydrated to ethyne
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 #14182)