Chemistry Past Questions

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130 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

130 questions
Question 1 of 20 130 total questions
Question 41
jamb 2019

Elements in the periodic table are arranged in the order of their

Aatomic numbers
Bmetallic character
Cmass number
Drelative atomic mass
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Question 42
jamb 2019

Which important nitrogen-containing compound is produced in Haber's process?

ANH\(_3\)
BNO\(_2\)
CNO
DHNO\(_3\)
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Question 43
jamb 2019

What mass of magnesium would be obtained by passing a current of 2 amperes for 2 hours 30 mins, through molten magnesium chloride?
[1 faraday = 96500C, Mg = 24]

A1.12g
B4.48g
C1.80g
D2.24g
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Question 44
jamb 2019

Which of the following gases contains the least number of atoms at s.t.p?

A1 mole of butane
B4 moles of chlorine
C3 moles of ozone
D7 moles of argon
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Question 45
jamb 2019

The IUPAC nomenclature of the compound
H\(_3\)C - CH(CH\(_3\)) - CH(CH\(_3\)) - CH\(_2\) - CH\(_3\)

A3,4- dimethylhexane
B2,3- dimethyl pentane
C2- ethyl hexane
D2,3- dimethylhexane
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Question 46
jamb 2019

A compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. If the molar mass of the compound is 180. Find the molecular formula.
[H = 1, C = 12, O = 16]

AC\(_3\)H\(_6\)O\(_3\)
BC\(_6\)H\(_6\)O\(_3\)
CC\(_6\)H\(_{12}\)O\(_6\)
DCH\(_2\)O
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Question 47
jamb 2019

In the reaction:
M + N → P
ΔH = +Q kJ

Which of the following would increase the concentration of the product?

AAdding a suitable catalyst
BIncreasing the concentration of P
CIncreasing the temperature
DDecreasing the temperature
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Question 48
jamb 2019

Sulphur exists in six forms in the solid state. This property is known as

AIsomerism
BAllotropy
CIsotopy
DIsomorphism
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Question 49
jamb 2019

In the reaction between sodium hydroxide and tetraoxosulphate (VI) solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralize 10cm\(^3\) of 1.25 molar tetraoxosulphate (vi) acid?

A25cm\(^3\)
B10cm\(^3\)
C20cm\(^3\)
D50cm\(^3\)
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Question 50
jamb 2019

Which of the following is a physical change?

AExposing white phosphorus to air
BBurning kerosene
CDissolving calcium in water
DFreezing ice cream
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Question 51
jamb 2019

Consider the equation below:

Cr\(_2\)O\(_7 ^{2-}\) + 6Fe\(^{2+}\) + 14H\(^{+}\) \(\to\) 2Cr\(^{3+}\) + 6Fe\(^{3+}\) + 7H\(_2\)O.

The oxidation number of chromium changes from

A+5 to +3
B+6 to +3
C-2 to +3
D+7 to +3
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Question 52
jamb 2019

Which of the following pairs cannot be represented with a chemical formula?

Aair and bronze
Bbronze and sodium chloride
Ccopper and sodium chloride
Dcaustic soda and washing soda
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Question 53
jamb 2019

Which of the following describes the chemical property of acids?

ANone of the above
BAcid + XCO\(_3\) \(\to\) Salt + H\(_2\)O + NH\(_3\)
CAcid + NaOH \(\to\) Normal salt + CO\(_2\)
DAcid + X\(_n\)CO\(_3\) \(\to\) Salt + H\(_2\)O + CO\(_2\)
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Question 54
jamb 2019

Which of the following pollutants will lead to the depletion of ozone layer?

Achlorofluorocarbon
Bcarbon (ii) oxide
Chydrogen sulphide
Dsulphur (iv) oxide
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Question 55
jamb 2019

Which two gases can be used for the demonstration of the fountain experiment?

ASO\(_4\) and NH\(_3\)
BSO\(_3\) and NH\(_3\)
CHCl and NH\(_3\)
DSO\(_2\) and CO
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Question 56
jamb 2019

A radioactive nucleus has a half-life of 20 years, starting with 100,000 particles, how many particles will be left exactly at the end of 40 years

A75,000 particles
B35,000 particles
C25,000 particles
D50,000 particles
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Question 57
jamb 2019

Na\(_2\)CO\(_3\) + 2HCl \(\to\) 2NaCl + H\(_2\)O + CO\(_2\)

The indicator most suitable for this reaction should have a pH equal to

A5
B7
C3
D9
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Question 58
jamb 2019

The molecular shape and bond angle of water are respectively

Alinear, 180°
Bbent, 109.5°
Ctetrahedral, 109.5°
Dbent, 105°
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Question 59
jamb 2019

Which of the following properties increases from left to right along the period but decreases down the group in the Periodic Table?
i. Atomic Number   ii. Ionization energy  iii. Metallic character  iv. Electron affinity

Aii and iii only
Bii and iv only
Ciii and iv only
Di and ii only
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Question 60
jamb 2019

At 27°C, 58.5g of sodium chloride is present in 250cm\(^3\) of a solution. The solubility of sodium chloride at this temperature is?
(molar mass of sodium chloride = 111.0gmol\(^{-1}\))

A2.0 moldm\(^{-3}\)
B0.25 moldm\(^{-3}\)
C1.0 moldm\(^{-3}\)
D0.5 moldm\(^{-3}\)
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