Chemistry Past Questions

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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 191
waec 2023

A consequence of global warming is

Aair pollution
BHigh Humidity
Cflooding
DWater pollution
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Question 192
waec 2023

How many unpaired electrons are present in \(_{26}Fe^{3+}\)?

A4
B2
C3
D5
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Question 193
waec 2023

Which of the following laws or theory cannot be explained by the application of the kinetic theory of gases?

ADalton's atomic theory
BCharle's law
CBoyle's law
DGay- Lussac's law
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Question 194
waec 2023

Carbon is deposited in the exhaust pipes of cars because of

Apresence of additives in petrol
Bincomplete combustion of petrol
Cpresence of carbon in petrol
Dcontamination of petrol with diesel
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Question 195
waec 2023

What takes place at the cathode during electrolysis?

AAnions lose electrons
BAnions are oxidized
CCations are oxidized
DCations are discharged.
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Question 196
waec 2023

Copper (II) ions are able to participate in co-ordinate covalent bonding because they

Aare coloured
Bare positively charged
Chave vacant d-orbital
Dhave unpaired electrons
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Question 197
waec 2023

Arrange the following compounds in decreasing order of their boiling points: \(NH_3\), HF, \(SiH_4\), \(CH_4\)

AHF,\(NH_3\), \(SiH_4\), \(CH_4\)
B\(CH_4\), \(SiH_4\), HF, \(NH_3\),
C\(NH_3\),\(CH_4\), \(SiH_4\), HF
D\(CH_4\), \(SiH_4\), \(NH_3\), HF
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Question 198
waec 2023

Consider the following reaction equation:
\(2SO_3(g) → 2SO_2(g) + O_2\)(g)
∆H = +198 kJ/mol
Which of the following statements about the reaction is correct?

A198 kJ of energy is given off
BThe reaction is exothermic
CThe reaction container would feel warm.
D198 kJ of energy is absorbed
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Question 199
waec 2023

The separation technique that is suitable for separating iodine from tetrachloromethane is

Asolvent extraction
Bdecantation
Cfractional distillation
Dfiltration
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Question 200
waec 2023

The salt solution formed firm a reaction between ethanoic acid and sodium hydroxide solution would be

Aamphoteric.
Bneutral
Cbasic
Dacidic
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Question 201
waec 2023

Which of the following equations does not illustrate correctly one of the reactions of chlorine?

A\(Ca(OH)_2 + Cl_2 → CaOCl_2 + H_2O\)
B\(Cl_2 + 2NaF → 2NaCl + F_2\)
C\(Cl_2 + 2NaOH → NaCl + NaClO + H_2O\)
D\(H_2S + Cl_2 → 2HCl + S\)
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Question 202
waec 2023

The pair of compounds that belongs to the same homologous series is

A\(C_2H_6\) and \(C_4H_{10}\)
B\(C_3H_8\) and \(C_3H_6\)
C\(C_2H_4\) and \(C_4H_{10}\)
D\(C_4H_{10}\) and \(C_5H_{10}\)
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Question 203
waec 2023

Which of the following equimolar solutions has the highest conductivity?

A\(H_2SO{_4(aq)}\)
B\(NaOH{_(aq)}\)
C\(H_2CO{_3(aq)}\)
D\(CH_3COOH{_4(aq)}\)
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Question 204
waec 2023

How many moles are there in 3.0 g of \(O_2\)? [O = 16.0]

A0.0093 moles.
B0.0930 moles.
C0.0625 moles.
D0.6250 moles.
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Question 205
waec 2023

Species that occur in a reaction pathway but not in the overall reaction are known as

AReactants
BInhibitors
CProducts
DIntermediates
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Question 206
waec 2023

A mixture containing two salts of different solubility can be separated by

Achromatography.
Bcrystallization.
Cdistillation.
Devaporation.
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Question 207
waec 2023

Which of the following statements is correct?

AAddition reactions occur between alkanes and chlorine.
BButane has a lower boiling point than propane.
CPentane has five isomers.
DAn alkane with 49 carbon atoms contains 100 hydrogen atoms
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Question 208
waec 2023

Dilute trioxonitrate (V) acid does not produce hydrogen when it reacts with metals because

Ait reacts with the product.
Bit is highly corrosive.
Cthere is no visible reaction.
Dit is a strong oxidizing agent.
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Question 209
waec 2023

Which of the following properties does not give evidence of the kinetic theory of matter?

ADiffusion
BMelting
CPolymerization
DEvaporation
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Question 210
waec 2023

Which of the elements in the table below would react more readily with chlorine?
      

Element

Ionization energy (KJ \(mol^{-1} \times 10^{-3}\))

W 12.0
X 21.0
Y 106.0
Z 200.0

 

AY and Z only
BX and Z only
CW and X only
DW and Z only
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