Home ยป Past Questions ยป Chemistry ยป Waec ยป 2023 ยป Page 3
43

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

  • A. 0.0093 moles.
  • B. 0.0930 moles.
  • C. 0.0625 moles.
  • D. 0.6250 moles.
View Answer & Discuss WAEC 2023
44

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

  • A. Reactants
  • B. Inhibitors
  • C. Products
  • D. Intermediates
View Answer & Discuss WAEC 2023
45

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

  • A. chromatography.
  • B. crystallization.
  • C. distillation.
  • D. evaporation.
View Answer & Discuss WAEC 2023
46

Which of the following statements is correct?

  • A. Addition reactions occur between alkanes and chlorine.
  • B. Butane has a lower boiling point than propane.
  • C. Pentane has five isomers.
  • D. An alkane with 49 carbon atoms contains 100 hydrogen atoms
View Answer & Discuss WAEC 2023
47

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

  • A. it reacts with the product.
  • B. it is highly corrosive.
  • C. there is no visible reaction.
  • D. it is a strong oxidizing agent.
View Answer & Discuss WAEC 2023
48

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

  • A. Diffusion
  • B. Melting
  • C. Polymerization
  • D. Evaporation
View Answer & Discuss WAEC 2023
49

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

 

  • A. Y and Z only
  • B. X and Z only
  • C. W and X only
  • D. W and Z only
View Answer & Discuss WAEC 2023
50

The formation of a bond between hydrogen and a highly electronegative atom results in

  • A. polarity
  • B. electrovalent bond.
  • C. dipole
  • D. metallic bond
View Answer & Discuss WAEC 2023
51

Alkenes can be manufactured by

  • A. the combustion of alkanes.
  • B. the cracking of hydrocarbons.
  • C. polymerization reactions.
  • D. addition of hydrogen to unsaturated vegetable oils.
View Answer & Discuss WAEC 2023
52

The following steps are scientific methods except

  • A. experimentation
  • B. problem identification
  • C. Analysis
  • D. Open-mindedness
View Answer & Discuss WAEC 2023
53

Which of the following reactions represents the hydrolysis of an alkanoate?

  • A. \(CH_3COOH + OH^- โ‡ŒH^+โ‡Œ CH_3COO^- + H_2O\)
  • B. \(CH_3COOH + C_2H_5OH โ‡ŒH^+โ‡Œ CH_3COOC_2H_5 + H_2O\)
  • C. \(CH_3COOC_2H_5 + H_2O โ‡ŒH^+โ‡Œ CH_3COO^- + CH_3CH_2OH\)
  • D. \(CH_3COOCH_2CH_3 + H_2O โ‡ŒH^+โ‡Œ CH_3COOH + CH_3CH_2OH\)
View Answer & Discuss WAEC 2023
54

The following statements are correct except

  • A. energy is released when liquids change to solids.
  • B. carbon atoms in gaseous methane are further apart than those in solid diamond.
  • C. there is large decrease in the volume of a solid metal when pressure is applied to it.
  • D. particles move faster in the gaseous state than in the liquid state.
View Answer & Discuss WAEC 2023
55

The vapour density of an organic compound with the molecular formula \(C_2H_4O_2\), is
[H=1.0, C=12.0, O= 16.0]

  • A. 40
  • B. 120
  • C. 65
  • D. 30
View Answer & Discuss WAEC 2023