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Chemistry
WAEC / WASSCE 2003
Chemical Energetics & Thermochemistry
Which of the following statements about an exothermic reaction is correct?
A
the products have less heat content than reactants
B
the system absorbs heat from the surrounding
C
the activation energy is high
D
the enthalpy change is positive
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 #36977)
Chemistry
WAEC / WASSCE 2003
Electrolysis & Electrochemical Cells
Determine the amount of electrons needed to deposit 6.4g of copper during the electrolysis of copper (ll) tetraoxosulphate (IV) solution [Cu = 64]
A
0.10 mole
B
0.20 mole
C
1.0 mole
D
2.0 mole
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 #36993)
Chemistry
WAEC / WASSCE 2003
Organic Chemistry I: Hydrocarbons & Crude Oil
A given fuel has an octane number of 100. This means that
A
the knocking tendency of the fuel is low
B
the fuel is a mixture of several hydrocarbons
C
a large amount of alkanes is present in the fuel
D
the fuel needs to be cracked before use
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 #36997)
Chemistry
WAEC / WASSCE 2003
Electrolysis & Electrochemical Cells
The equation for the reaction at the anode during the electrolysis of concentrated sodium chloride solution is
A
2CI- (aq) → CI,sub>2(g) + 2e-
B
40H-(aq) → 2H2O(I) + O2(g) + 4e -
C
Na+(aq) + e- → Na(s)
D
2H+(aq) + 2e- → H2(g)
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 #37001)
Chemistry
WAEC / WASSCE 2003
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following compounds has the same empirical formula as benzene?
A
C2H2
B
C2H4
C
C4H6
D
C6H12
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 #37012)
Chemistry
WAEC / WASSCE 2003
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
Solution
Wine containing 8% to 17% ethanol can be converted to gin containing about 40% ethanol by
A
evaporation
B
distilation
C
fermentation
D
oxidation
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
Gin is a distilled alcoholic beverage that typically contains about 40% ethanol. To produce gin from wine, the wine must undergo a process called distillation. Distillation involves heating the wine to vaporize the ethanol, which has a lower boiling point than water, and then condensing the vapor to collect the ethanol. This results in a much higher concentration of ethanol in the final product. Fermentation, which is the process by which wine is produced, can only produce ethanol concentrations of up to about 17%. Therefore, distillation is necessary to increase the ethanol content of the wine to the level required for gin.
Source: Myschool Past Questions Archive (Record #37014)
Chemistry
WAEC / WASSCE 2003
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
Which of the following substances could be responsible for the banana taste of a food flavour?
A
Methylbenzene
B
Butanol
C
Ethanol
D
Pentylethanoate
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 #37015)
Chemistry
WAEC / WASSCE 2003
Oxidation, Reduction & Redox Reactions
Solution
What is the organic product of the reaction of C2H 5OH with excess acidified K 2Cr 2O7(aq)?
A
CH3COOH
B
C2H5OC2H5
C
HCOOCH 3
D
C2H5CHO
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
When C\(_2\)H\(_5\)OH (ethanol) reacts with excess acidified K\(_2\)Cr\(_2\)O\(_7\) (potassium dichromate), it produces ethanoic acid (CH\(_3\)COOH) as the main product; essentially, the alcohol is oxidized to a carboxylic acid by the strong oxidizing agent potassium dichromate.
Source: Myschool Past Questions Archive (Record #37016)
Chemistry
WAEC / WASSCE 2003
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
The reaction of vegetable oil with a solution of wood ash is
A
saponification
B
neutralization
C
hydrogenation
D
esterification
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 #37017)
Chemistry
WAEC / WASSCE 2003
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
Solution
What process does the following equation represent ? n(\(C_6\)H\(_{10}\)\(O_5\)) + n\(H_2\)O → n\(C_6\)H\(_{12}\)\(O_6\) ?
A
Polymerization of glucose
B
Hydrolysis of starch
C
Fermentation of sugar
D
Dehydration of carbohydates
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
The enzyme amylase is secreted out of the cells (an exoenzyme) into the surrounding media, catalyzing the breakdown of starch into smaller sugars which can then be absorbed by the cells for use.
Source: Myschool Past Questions Archive (Record #37018)
Chemistry
WAEC / WASSCE 2003
Oxidation, Reduction & Redox Reactions
When excess ethene is shaken with acidified KMnO4 solution, the product obtained is
A
ethane
B
ethanal
C
ethane - 1, 2 - diol
D
ethanoic acid
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 #37019)
Chemistry
WAEC / WASSCE 2003
Nature of Matter & Separation Techniques
Solution
What volume of 0.20 mol dm -3 NaOH solution would yield 5.0 g of NaOH on evaporation to dryness? [NaOH = 40g mol-1]
A
400 cm3
B
625 cm3
C
1000 cm3
D
1600 cm 3
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
Conc. g/dm3 = 0.20 x 40 gmol -1 = 8 g/dm3
1000 cm3 of 0.20m NaOH contains 8g of NaOH :. 5g of NaOH will be contained in 5/8 x 1000 x 625cm3
Source: Myschool Past Questions Archive (Record #37020)
Chemistry
WAEC / WASSCE 2003
Metals, Transition Elements & Extraction
Which of the following compound is used for removing impurities from bauxite?
A
NaOH
B
CaCO3
C
Na3AIF6
D
H2SO4
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 #37021)
Chemistry
WAEC / WASSCE 2003
Metals, Transition Elements & Extraction
What is the main impurity in haematite?
A
CaSiO3
B
CaCO3
C
SiO3
D
Fe2O3
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 #37022)
Chemistry
WAEC / WASSCE 2003
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
When a sample of water was boiled, it lathered more readily with soap. it can be concluded that the sample most likely contained
A
magnesium tetraoxosulphate (VI)
B
suspended solids
C
Organic impurities
D
calcium hydrogentrioxocarbonate (IV)
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 #37023)