Chemistry Past Questions

Study and practice Chemistry past questions with answers and detailed explanations. Then test your knowledge using our interactive CBT practice platform and prepare confidently for your upcoming examinations.

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

50 questions
Question 1 of 20 50 total questions
Question 1
waec 2021

Which of the following scientists discovered the electrons?

AJoseph J. Thompson
BJames Chadwick
CAmedeo Avogadro
DErnest Rutherford
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Question 2
waec 2021

A coordinate covalent bond could be formed between?

ANH\(_{3}\) and PCl\(_{3}\)
BBCl\(_{3}\) and AlCl\(_{3}\)
CBCl\(_{3}\) and NH\(_{3}\)
DH\(^{+}\) and AlCl\(_{3}\)
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Question 3
waec 2021

Electrovalent compounds normally ------------

Ahave low boiling points
Bhave mobile electrons
Cconduct electricity in the solid state
Ddissolve in polar solvent
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Question 4
waec 2021

Which of the following statements about elements in Group VII is correct?

ABr\(_{2}\) will oxidize CI\(^{-}\)
BF\(_{2}\) has the least tendency to be reduced
CCl\(_{2}\) will oxidize I\(^{-}\)
Dl\(_{2}\) is a stronger oxidizing agent than F\(_{2}\)
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Question 5
waec 2021

Which of the following pairs of molecules form hydrogen bonds?

AC\(_{2}\)H\(_{5}\)OH and CH\(_{3}\)OH
BCH\(_{3}\)OH and H\(_{2}\)
CH\(_{2}\)S and CH\(_{4}\)
DNH\(_{3}\) and SO\(_{2}\)
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Question 6
waec 2021

The isotopes of neon are represented by the symbols \(^{20}\)\(_{x}\) Ne, \(^{21}\) \(_{y}\) Ne, and \(^{22}\) \(_{z}\) Ne. The relationship between x, y, and z is?

Ax > y > z
Bx < y < z
Cx = y= z
Dx < z < y
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Question 7
waec 2021

How many molecules of oxygen would occupy a volume of 2.24 cm\(^{3}\) at s.t.p?

[Molar volume at s.t.p = 22,400 cm\(^{3}\), Avogadro's number = 6.02 x 10\(^{23}\)]

A3.01 x 10\(^{20}\)
B3.01 x 10\(^{27}\)
C6.02 x 10\(^{19}\)
D6.02 x 10\(^{27}\)
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Question 8
waec 2021

The energy profile diagram illustrates-------------

Aan endothermic reaction
Ban exothermic reaction
Ca spontaneous reaction
Da redox reaction
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Question 9
waec 2021

The enthalpy change of the reaction is------------

AE\(_{A}\)
BE\(_{B}\)
CE\(_{C}\)
DE\(_{D}\)
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Question 10
waec 2021

The activation energy of the reaction is

AE\(_{A}\)
BE\(_{B}\)
CE\(_{C}\)
DE\(_{D}\)
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Question 11
waec 2021

Protons and electrons are called fundamental particles because they----------

Aare indivisible
Bhave different charges
Care the lightest particles
Dare found in all matter
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Question 12
waec 2021

The region around the nucleus where electrons can be located is called?

Aa spectra
Ban orbital
Ca quanta
Da field
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Question 13
waec 2021

The following ions have the same electron configuration except 

\(_{8}\)O, \(_{12}\)Mg, \(_{13}\)AI, \(_{17}\)CI

ACI\(^{-}\)
BO\(^{2-}\)
CMg\(^{2+}\)
DAI\(^{3+}\)
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Question 14
waec 2021

An element, Q, contains 69% of\(^{63}\)Q and 31% of \(^{65}\)Q. What is the relative atomic mass of Q?

A63.0
B63.6
C65.0
D69.0
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Question 15
waec 2021

Potassium trioxonitrate (V) can be obtained from its solution by----------

Adistillation
Bevapoartion
Ccrystallization
Dfiltration
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Question 16
waec 2021

Which of the following statements is correct about ionization energy? It

Adecreases across the periods
Bresults in the formation of an anion
Ccauses Metalic nuclei to disintegrate
Ddecreases down the group
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Question 17
waec 2021

Which of the following species has the largest ionic radius

AK\(^{+}\)
BCI\(^{-}\)
C
DCa\(^{2+}\)
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Question 18
waec 2021

What is the empirical formula of a hydrocarbon containing 0.160 moles of carbon and 0.640 moles of hydrogen

ACH\(_{2}\)
BCH\(_{3}\)
CCH\(_{4}\)
DC\(_{2}\)H\(_{4}\)
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Question 19
waec 2021

What is the concentration of a solution which contains 0.28g of potassium hydroxide in 100 cm\(^{3}\) of solution [KOH = 56]

A0.01 mol dm\(^{-3}\)
B0.05 mol dm\(^{-3}\)
C0.10 mol dm\(^{-3}\)
D0.50 mol dm\(^{-3}\)
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Question 20
waec 2021

Student X titrated 25 cm\(^{3}\) of Na\(_{2}\)CO\(^{3}\) with 0.1 mol dm\(^{-3}\) HCI, using methyl orange as indicator. Student Y carried out the same exercise but used phenolphthalein as an indicator. Which of the following statements about the titration is true?

Ahydrogen chloride gas was released in the reactions in both titrations
Bthe titer values obtained from the titration are equal
Cthe titer value obtained by Y is twice that of X
D
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