Chemistry Past Questions

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1,623 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

1,623 questions
Question 1 of 20 1,623 total questions
Question 211
waec 2017

Which of the following statements is NOT a chemical property of an acid?

AEvolution of ammonia when heated with ammonium salts
BEvolution of carbon dioxide gas when added to a trioxocarbonate (IV) salt
CFormation of salt and water with alkalis
DFormation of salt and hydrogen gas with reactive metals
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Question 212
waec 2017

A hydrocarbon contained 14.3% hydrogen. The empirical formula for the hydrocarbon is   [H= 1.0, C= 12.0]

A\(CH\)
B\(CH_{2}\)
C\(CH_{3}\)
D\(CH_{4}\)
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Question 213
waec 2017

Which of the following gases is not acidic?

A\(SO_{3}\)
B\(NO_{2}\)
C\(Co_{2}\)
DCO
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Question 214
waec 2017

When Magnesium reacts with oxygen, heat is 

Aabsorbed and the reaction is endothermic
Bevolved and the reaction is endothermic
Cevolved and the reaction is exothermic
Dabsorbed and the reaction is exothermic
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Question 215
waec 2017

The number of atoms present in 2.5moles of a triatomic gas is equivalent to   [1mole = \(6.02\times 10^{23}\)]

A\(2.5\times 10^{23}\)
B\(1.5\times 10^{23}\)
C\(1.5\times 10^{24}\)
D\(2.5\times 10^{24}\)
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Question 216
waec 2017

In a saturated solution at a given temperature, the undissolved solutes are in equilibrium with

Athe solvent
Bdissolved solute particles
Cthe saturated solution
Dinsoluble solute particles
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Question 217
waec 2017

Graphite and Diamond are similar in that they

Ahave octahedral shape
Bhave same density
Cform carbon(IV) oxide on combustion
Dconduct electricity
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Question 218
waec 2017

A 0.1\(moldm^{-3}\) solution of sodium hydroxide was diluted with distilled water to 0.001\(moldm^{-3}\). What is the dilution factor?

A1000.00
B100.00
C10.00
D0.01
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Question 219
waec 2017

Which of the following statements about endothermic reaction is correct?

AActivation energy is high
BA catalyst is required
CIt occurs reversibly
DHeat energy is absorbed
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Question 220
waec 2017

The use of diamond in abrasives is due to its

Ahigh melting point
Bhardness
Coctahedral shape
Ddurability
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Question 221
waec 2017

The properties of a good primary standard include the following except

Ahigh molecular mass
Blow molecular mass
Chigh degree of purity
Dreadily available
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Question 222
waec 2017

The bond angle in tetrahedral molecules such as tetrachloromethane is 

A180.0°
B109.5°
C105.5°
D90.0°
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Question 223
waec 2017

Which of the following statements is correct?

ACovalent compounds would readily ionize in solution
BCovalent compounds consist of ions
CHydrogen bond is formed between a metal and a non-metal
DIonic compounds in solution would conduct electricity
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Question 224
waec 2017

The ionization energy is affected by the following factors except

Adistance of the outermost electron(s) from the nucleus
Bsize of the positive nuclear charge
Cability to attract shared electron(s)
Dscreening effect of the inner electron(s)
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Question 225
waec 2017

The oxidation number of X in \(XO_{4}^{3-}\) is

A+1
B+3
C+4
D+5
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Question 226
waec 2017

Which of the following substances does not have van der Waals' forces?

ACopper
BGraphite
CNeon
DIodine crystals
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Question 227
waec 2017

Which of the following metals has the strongest metallic bond?

A\(_{13}Al\)
B\(_{19}K\)
C\(_{12}Mg\)
D\(_{11}Na\)
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Question 228
waec 2017

Which of the following arrangements indicates the correct decreasing order of ionization energy of period 3 elements?

ANa, Al, P, Cl
BCl, P, Al, Na
CNa, P, Cl, Al
DAl, Na, P, Cl
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Question 229
waec 2017

The oxidation number of nitrogen in \(Pb(NO_{3})_{2}\) is

A+2
B+3
C+4
D+5
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Question 230
waec 2017

The reason for the decrease in the atomic size of elements across a period is that

Anuclear charge increases while the outermost electrons are drawn closer to the nucleus
Bnuclear charge decreases while the outermost electrons are drawn closer to the nucleus
Cvalence electrons increase across the period while the valence shell remains constant
Dnuclear charge decreases while the distance of the valence shell from the nucleus is increasing
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