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.

4,306 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

4,306 questions
Question 1 of 20 4,306 total questions
Question 451
waec 2018

Which of the following properties would not influence electrovalent bond formation?

AElectronegativity
BElectron Affinity
CIonization potential
DCatalytic ability
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Question 452
waec 2018

The solubility of \(CO_{2}\) in water can be accounted for by

AVan der Waal's forces
BIonic attraction
Cdipole attraction
Dcovalent bonding
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Question 453
waec 2018

The bonding pair of electrons in a Hydrogen Chloride molecule is pulled towards the chlorine atom because 

Achlorine has a larger atomic size
Bchlorine has a larger atomic mass
Cchlorine is more electronegative
Dthere is no bonding orbitals within the hydrogen atom
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Question 454
waec 2018

What is the total number of shared pair of electrons in the compound above?

A5
B8
C10
D12
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Question 455
waec 2018

The atomic number of an isotope of hydrogen is equal to its mass number because it

Ahas a totally filled valence shell
Bhas a high charge to mass ratio
Cdoes not contain neutrons
Dexhibits isotopy
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Question 456
waec 2018

Which of the following electron configurations represents the transition element Chromium \(_{24}Cr\)?

A\(1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{4}\)
B\(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{6}\)
C\(1s^{2}2s^{2}2p^{6}3s^{2}3d^{4} 4s^{1}\)
D\(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}3d^{5}\)
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Question 457
waec 2018

Common Salt (NaCl) is used to preserve foods. Which of the following properties can be used to determine its purity before use?

ASolubility in water
BMelting point
CRelative density
DCrystalline nature
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Question 458
waec 2018

Atoms are electrically neutral because they

Ado not conduct electricity
Bcontain equal number of protons and electrons
Care composed of neutrons and electrons
Dcannot be attracted by electromagnetic field.
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Question 459
waec 2018

What is the relative molecular mass of a compound which has empirical formula \(CH_{2}O\)?   [C= 12, H= 1, O= 16]

A42
B45
C126
D180
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Question 460
waec 2018

The law of definite proportions states that

Apure samples of the same compound contain the same elements combined in the same proportion by mass
Bpure samples of substances are in the same proportion by mass
Cchemical compounds are pure because they contain the same elements
Dmatter can neither be created nor destroyed.
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Question 461
waec 2018

Analysis of a hydrocarbon shows that it contains 0.93g of Carbon per gram of the compound. The mole ratio of carbon to hydrogen in the compound is [H = 1.0, C=12.0]

A1:1
B1:2
C2:1
D2:3
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Question 462
waec 2018

Which of the following statements is true about ionic radius? Ionic radius

Aincreases as nuclear charge increases
Bdecreases as nuclear charge increases
Cdecreases as nuclear charge decreases
Dremains constant as nuclear charge increases
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Question 463
waec 2018

Which of the following methods can be used to seperate blood cells from plasma?

ACentrifugation
BFiltration
CChromatography
DDistillation
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Question 464
waec 2018

The change in the oxidation state of iron in the reaction represented by the equation:  \(2FeCl_{3} + H_{2}S \to 2FeCl_{2} + 2HCl + S\)  is

A+2 to +3
B0 to +2
C+3 to +2
D+3 to 0
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Question 465
waec 2018

The empirical formula of a compound containing 0.067mol Cu and 0.066mol O is    [Cu = 63.5, O = 16]

A\(Cu_{2}O\)
B\(CuO\)
C\(CuO_{2}\)
D\(CuO_{4}\)
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Question 466
waec 2018

When zinc is added to AgNO\(_{3}\) solution, crystals of silver forms on the zinc surface. This indicates that zinc is

Aoxidised
Breduced
Cdecomposed
Ddissociated
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Question 467
waec 2018

The strength of metallic bonds depends on the 

Acharge density of the atoms
Bductility of the metal
Cnumber of valence electrons
Dtotal number of electrons in the atom
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Question 468
waec 2018

How many atoms are contained in 0.2moles of nitrogen? \([N_{A} = 6.02 \times 10^{23}]\)

A\(1.20 \times 10^{23}\)
B\(2.41 \times 10^{23}\)
C\(3.62 \times 10^{23}\)
D\(4.82 \times 10^{23}\)
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Question 469
waec 2018

When chlorine is passed through a sample of water, the pH of the water sample would be

A< 7
B> 7
C= 7
D0
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Question 470
waec 2018

One of the criteria for confirming the purity of benzene is to determine its

Aheat capacity
Bboiling point
Cmass
Dcolour
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