Question Library
Browse, filter, and study verified past examination questions with step-by-step mathematical reasoning.
Searching 18,000+ Questions...
Sifting topics, KaTeX formulas & verified solutions
Showing 14506–14520 of 29821 verified questions
Sort by:
Chemistry
UTME / JAMB 2006
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
Diagram
Solution
The oxidation of the compound above produces
Attached Figure / Diagram
A
2-butanone
B
2-butanal
C
3-butanal
D
3-butanone
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
The compound above is Butan-2-ol or 2- butanol. Oxidizing butan-2-ol (a secondary alcohol) yields butan-2-one (also known as methyl ethyl ketone or 2-butanone), a ketone.
In summary, when primary alcohols are oxidized, they can form aldehydes or carboxylic acids, depending on the reaction conditions and the strength of the oxidizing agent used. When secondary alcohols are oxidized, they form ketones. Tertiary alcohols are generally not readily oxidized under typical conditions, and they do not form aldehydes, ketones, or carboxylic acids. The reason is because the carbon atom attached to the hydroxyl (-OH) group in a tertiary alcohol is already bonded to three other carbon atoms. This means there are no hydrogen atoms available on that carbon for oxidation to occur.
Source: Myschool Past Questions Archive (Record #31641)
Chemistry
UTME / JAMB 2006
Stoichiometry, Mole Concept & Volumetric Analysis
Diagram
Solution
2-methylbut-2-ene has the structure
Attached Figure / Diagram
A
A
B
B
C
C
D
D
medium Difficulty
Verified Correct Answer: Option D
Chemical Principles & Mechanism
The structure of 2-methylbut-2-ene in in option D.The Carbon, carbon double bond is on C-2 with a substituent group,Methyl (CH\(_3\)) also on C-2 with the parent name being but-2-ene, since the longest carbon chain is four and the double bond is on carbon 2.
Source: Myschool Past Questions Archive (Record #31648)
Chemistry
UTME / JAMB 2006
Organic Chemistry II: Functional Groups, Polymers & Biomolecules
Diagram
Solution
Which of the following functional groups will give gas bubbles when treated with a saturated solution of sodium hydrogen trioxocarbonate (IV)?
Attached Figure / Diagram
A
A
B
B
C
C
D
D
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
When a carboxylic acid (RCOOH) reacts with sodium bicarbonate (NaHCO\(_3\)), it forms a salt (RCOONa), water (H\(_2\)O), and carbon dioxide (CO\(_2\)). The carbon dioxide gas produced in this reaction is what causes the bubbles or effervescence observed.
RCOOH + NaHCO\(_3\) → RCOONa + H\(_2\)O + CO\(_2\)
This reaction is a simple and reliable test to distinguish carboxylic acids from other organic compounds, as most other functional groups (like alcohols or phenols) are not acidic enough to react with bicarbonate and produce a gas.
Source: Myschool Past Questions Archive (Record #31650)
Chemistry
WAEC / WASSCE 2006
Stoichiometry, Mole Concept & Volumetric Analysis
How many orbitals are in the d-sub shell?
A
1
B
3
C
5
D
7
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 #37105)
Chemistry
WAEC / WASSCE 2006
Atomic Structure, Orbitals & Nuclear Chemistry
Solution
An element X has isotopic masses of 6 and 7. if the relative abundance is 1 to 12.5 respectively, what is the relative atomic mass of X?
A
6.0
B
6.1
C
6.9
D
7.0
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
Contribution by isotope 6 = 6 x 1 = 6
contribution by isotope 7 = 7 x 12.5 = 87.5
This contribution is made by 1 + 12.5 = 13.5 atoms
Relative atomic mass of = 87.5 + 6 = 93.5/13.5 = 6.9
Source: Myschool Past Questions Archive (Record #37106)
Chemistry
WAEC / WASSCE 2006
Atomic Structure, Orbitals & Nuclear Chemistry
Solution
An atom 23892X decays by alpha particle emission to give an atom Y. The atomic number and mass number of Y are
A
90 and 234 respectively
B
91 and 238 respectively
C
92 and 236 respectively
D
93 and 238 respectively
medium Difficulty
Verified Correct Answer: Option A
Chemical Principles & Mechanism
23892 X 234 90Y + 4 2 He Atomic number is 90 while mass number is 234
Source: Myschool Past Questions Archive (Record #37107)
Chemistry
WAEC / WASSCE 2006
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
If 1 mole of sodium contains 6 x 1023 atoms, how many atoms are contained in 0.6 g of sodium? [Na = 23]
A
1.56 x 1023
B
1.56 x 1022
C
3.6 x 1023
D
3.6 x 1022
medium Difficulty
Verified Correct Answer: Option B
Chemical Principles & Mechanism
23g of sodium contain 6 x 1023 atoms :. 0.6g of sodium will contain \(\frac{0.6 x 6 x 1023}{23}/) = 1.56 x 1022
Source: Myschool Past Questions Archive (Record #37108)
Chemistry
WAEC / WASSCE 2006
Stoichiometry, Mole Concept & Volumetric Analysis
Solution
If 20 cm3 of distilled water is added to 80cm 3 of 0. 50 mol dm-3 hydrochloric acid, the new concentration of the acid will be
A
0.10mol dm-3
B
0.20mol dm-3
C
0.40mol dm-3
D
2.00mol dm-3
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
\(V_1\) = 80cm3, \(C_1\) = 0.5mol/dm3
\(C_2\) = ? \(V_2) = 20cm3 + 80cm3 = 100cm3
using the dilution formula, \(C_1 V_1 = C_2 V_2\)
0.5 x 80 = \(C_2\) x 100
\(C_2 = \frac{ 40}{100}\) = 0.4mol\(dm^{-3}\)
Source: Myschool Past Questions Archive (Record #37109)
Chemistry
WAEC / WASSCE 2006
Acids, Bases, pH & Salts
Solution
Consider the reaction represented by the equation. 2NaHCO3(s) \(\rightarrow\) 2Na2CO 3(S) + CO 2(g) + H2O(g) what volume of carbon (IV)oxide at s.t.p is evolved when 0. 5 moles of NaHCO3 is heated? [Molar volume = 22.4 dm3 at s.t. p]
A
1.12dm3
B
2.24dm3
C
5.6dm3
D
56.0dm3
medium Difficulty
Verified Correct Answer: Option C
Chemical Principles & Mechanism
2NaHCO3(s) \(\rightarrow\) 2Na2CO 3(S) + CO 2(g) + H2O(g)
2 moles of 2NaHCO3(s) produces 22.4dm3 of CO2
0.5 moles of 2NaHCO3 will produce \(\frac{0.5 \times 22.4}{2}\)
= \(\frac{11.2}{2}\)
= 5.6 dm3
Source: Myschool Past Questions Archive (Record #37110)
Chemistry
WAEC / WASSCE 2006
Chemical Energetics & Thermochemistry
Considered the reaction: H+(aq) + OH - (aq) → H2O
(l). The energy change taking place in the reaction above is enthalpy of
A
formation
B
hydration
C
neutralization
D
solution
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 #37111)
Chemistry
WAEC / WASSCE 2006
Chemical Energetics & Thermochemistry
Which of the following processes is an endothermic reaction?
A
Dissolving NH4CI crystals in water
B
Addition of concentrated H2SO4
C
Dissolving NaOH pellets in water
D
Passing SO3 gas into water
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 #37112)
Chemistry
WAEC / WASSCE 2006
Acids, Bases, pH & Salts
Which of the following aqueous methods cannot be used to distinguish between a strong acid and a a weak acid?
A
Conductivity measurement
B
Measurement of pH
C
Measurement of heat of neutralization
D
Action on starch iodide paper
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 #37113)
Chemistry
WAEC / WASSCE 2006
Stoichiometry, Mole Concept & Volumetric Analysis
The indicator used in neutralizing CH3COOH and NaOH solution has pH range of
A
3-5
B
7-8
C
8-103
D
10-12
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 #37114)
Chemistry
WAEC / WASSCE 2006
Stoichiometry, Mole Concept & Volumetric Analysis
When aqueous ammonia is added to one of the following solutions,a white precipitate which dissolved in excess ammonia is formed Identify the solution.
A
ZnCl2(aq)
B
Pb(NO3)2(aq)
C
CuSO4(aq)
D
FeSO4(aq)
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 #37115)
Chemistry
WAEC / WASSCE 2006
Stoichiometry, Mole Concept & Volumetric Analysis
Which of the following compounds absorbs moisture from the atmosphere and dissolves in it?
A
FeCI3
B
MgSO4.7H2O
C
Na2SO 4
D
KCI
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 #37116)