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Chemistry
NECO SSCE 2008
Metals, Transition Elements & Extraction
Bauxite is the ore of
A
aluminium
B
calcium
C
Iron
D
sodium
E
magnesium
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 #43556)
Chemistry
NECO SSCE 2008
Particulate Nature of Matter, Laws & Formulae
Solution
An element Z has a combining power of 3. Which of the following formulae is correct of its compound?
A
ZS3
B
ZSO3
C
ZS04
D
Z203
E
Z3Cl2
medium Difficulty
Verified Correct Answer: Option D
Chemical Principles & Mechanism
Since element Z has a combining power of 3, the correct formulae will be Z\(_2\)O\(_3\). Which means that Oxygen has a valency of 2. However, as they combine both Z and O will exchange their valencies. i.e Z takes the 2 from O while O takes the 3 from Z. Hence the formula will be Z\(_2\)O\(_3\).
Source: Myschool Past Questions Archive (Record #43558)
Chemistry
NECO SSCE 2008
Stoichiometry, Mole Concept & Volumetric Analysis
The following acids are monobasic EXCEPT
A
dioxonitrate (Ill) acid
B
ethanedioic acid
C
hydrobromic acid
D
methanoic acid
E
oxochlorate (I) 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 #43559)
Chemistry
NECO SSCE 2008
Periodic Table & Periodicity
Which of these arrangement of elements is in order of increasing ionization energy?
A
Boron, Carbon, Flourine, Nitrogen
B
Boron, Carbon, Nitrogen, Flourine
C
Carbon, Boron, Nitrogen, Flourine
D
Flourine, Nitro9en, Carbon, Boron
E
Nitrogen, Flourine, Carbon, Boron
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 #43560)
Chemistry
NECO SSCE 2008
Stoichiometry, Mole Concept & Volumetric Analysis
The gas in air used by plants for photosynthesis is
A
Argon
B
Carbon (IV) oxide
C
Nitrogen
D
Oxygen
E
Water vapour.
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 #43562)
Chemistry
NECO SSCE 2008
Acids, Bases, pH & Salts
When sodium hydroxide solution is added to a solution of zinc salt, the white precipitate formed re-dissolve in excess sodium hydroxide because
A
sodium hydroxide is a strong alkali
B
sodium is more reactive than zinc
C
zinc is more reactive than sodium
D
zinc hydroxide is amphoteric
E
zinc hydroxide is unstable
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 #43563)
Chemistry
NECO SSCE 2008
Stoichiometry, Mole Concept & Volumetric Analysis
A chemical system is at equilibrium when
A
δ G is positive
B
δ G is zero
C
δ S is negative
D
δ S is positive
E
δ S is zero.
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 #43564)
Chemistry
NECO SSCE 2008
Kinetic Theory of Matter & Gas Laws
Brownian motion explains
A
Boyle’s law
B
Collision theory
C
Laws of chemical combination
D
Molecular motion in liquids and gases
E
Vibrational motion in liquids.
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 #43565)
Chemistry
NECO SSCE 2008
Stoichiometry, Mole Concept & Volumetric Analysis
The reaction of hydrochloric acid and calcium trioxocarbonate (IV) produces
A
calcium chloride, carbon (IV) oxide and water
B
calcium chloride, and trioxocarbonate (IV) acid
C
calcium hydroxide, carbon (IV) oxide and chlorine gas
D
calcium hydroxide, carbon (IV) oxide and water
E
calcium metal and 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 #43567)
Chemistry
NECO SSCE 2008
Atomic Structure, Orbitals & Nuclear Chemistry
If two elements X and Z with electronic configurations 2,8.3 and2,8,6 respectively combine, the compound formed will have the formula
A
XZ
B
XZ2
C
X2Z
D
X2Z3
E
X3Z2
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 #43569)
Chemistry
NECO SSCE 2008
Particulate Nature of Matter, Laws & Formulae
The following gases are diatomic EXCEPT
A
Fluorine
B
Helium
C
Hydrogen
D
Nitrogen
E
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 #43571)
Chemistry
NECO SSCE 2008
Acids, Bases, pH & Salts
Which of these is NOT a physical property f water?
A
Can be used to dissolve organic substances
B
Has a boiling point of 100 ° C
C
Has a density of 19cm3 at 40 °C
D
Has a freezing point of 0 ° C
E
is neutral to litmus
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 #43573)
Chemistry
NECO SSCE 2008
Electrolysis & Electrochemical Cells
During the electrolysis of sodium Chloride solution, hydrogen is discharged at the carbon cathode because
A
hydrogen ions are in greater concentration than sodium ions.
B
hydrogen is higher than sodium in the electrochemical series.
C
hydrogen is lower than sodium in the electrochemical series.
D
of the nature of the electrodes.
E
the concentration of sodium ions is greater than that of the hydrogen ion in the electrolyte.
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 #43575)
Chemistry
NECO SSCE 2008
Nature of Matter & Separation Techniques
Chromatography is used to separate components of mixtures which differ in their rates of
A
diffusion
B
migration
C
reaction
D
sedimentation
E
sublimation.
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 #43576)
Chemistry
NECO SSCE 2008
Electrolysis & Electrochemical Cells
Solution
The electrode potential in volts of 2H\(^+\)(aq) / H\(_2\)(q) system is
A
-2.87
B
-2.71
C
0.8
D
1.68
E
\( 0 \)
medium Difficulty
Verified Correct Answer: Option E
Chemical Principles & Mechanism
The electrode potential of 2H\(^+\)(aq) / H\(_2\)(q) system is defined as 0 volt. This is because the standard hydrogen electrode(SHE) is defined as the reference point of measuring electrode potentials, and it is assigned a value of 0 volts. The SHE consists of a platinum electrode immersed in a solution with a hydrogen ion concentration of 1 M, and bubbled with hydrogen gas at a pressure of 1 atm.
Source: Myschool Past Questions Archive (Record #43577)