Home Β» Past Questions Β» Chemistry Β» Waec Β» 2022
1

Which of the following sketches is a graphical representation of Boyle’s law?

  • A. A
  • B. B
  • C. C
  • D. D
View Answer & Discuss WAEC 2022
2

Which of the following scientists formulated the law of conservation of mass?

  • A. A. Lavoisier
  • B. J. Dalton
  • C. R. Boyle
  • D. J. Proust
View Answer & Discuss WAEC 2022
3

The first definition of an element was made by

  • A. J. Dalton.
  • B. A. Lavoisier.
  • C. R. Boyle.
  • D. J. J. Thompson.
View Answer & Discuss WAEC 2022
4

Charcoal is used in the decolourization of sugar because of its

  • A. absorption property.
  • B. amorphous property.
  • C. oxidizing property.
  • D. adsorption property.
View Answer & Discuss WAEC 2022
5

If the molar mass of X(HCO3)\(_{2}\) is 162 g mol\(^{-1}\), determine the relative atomic mass of X.
[H = 1.0, C = 12.0, 0 = 16.0]

  • A. 40
  • B. 48
  • C. 61
  • D. 101
View Answer & Discuss WAEC 2022
6

Which of the following processes occur during fractional distillation of petroleum?

  • A. Condensation and diffusion
  • B. Diffusion and evaporation
  • C. Diffusion and sublimation
  • D. Evaporation and condensation
View Answer & Discuss WAEC 2022
7

Which of the following oxides is amphoteric?

  • A. Carbon(II) oxide
  • B. Nitrogen(IV) oxide
  • C. Lead(II) oxide
  • D. Calcium oxide
View Answer & Discuss WAEC 2022
8

Consider the following table

Substitute Meltig point / ΒΊC Boiling  point / ΒΊC
P – 78 -25
Q – 8 40
R  – 6 150
S 44 280

Which of the substances is a liquid at room temperature and rapidly evaporates on exposure to air?

  • A. P
  • B. Q
  • C. R
  • D. S
View Answer & Discuss WAEC 2022
9

Electropositivity of elements across the periodic table normally

  • A. remains constant down the group
  • B. increases across the period
  • C. decreases across the period
  • D. decreases down the group
View Answer & Discuss WAEC 2022
10

The atom with the electron configuration
1s\(^{2}\)2s\(^{2}\)2p63s\(^{2}\)3p\(^{6}\)3d\(^{10}\)4s\(^{2}\)4p\(^{4}\) is in

  • A. period 4, p- block
  • B. period 3, p- block
  • C. period 4, d- block
  • D. period 3, d- block
View Answer & Discuss WAEC 2022
11

Which of the following statements about atoms of a metal is correct? They

  • A. readily accept electrons
  • B. are soft
  • C. are held together by covalent bond
  • D. are held together by a sea of electron cloud
View Answer & Discuss WAEC 2022
12

An oxide has the following properties. It

I. is a white powder
II. reacts with HCI.
III. reacts with NaOH
IV. is insoluble in water
The oxide is

  • A. alkaline
  • B. amphoteric
  • C. acidic
  • D. neutral
View Answer & Discuss WAEC 2022
13

The electron configuration of carbon atom in its excited state is

  • A. 1s\(^{2}\)2s\(^{2}\)2px\(^{2}\)2py\(^{0}\)
  • B. 1s\(^{2}\)2s\(^{2}\)2px\(^{1}\)2py\(^{1}\)
  • C. 1s\(^{2}\)2s\(^{1}\)2px\(^{1}\)2py\(^{1}\)2pz\(^{1}\)
  • D. 1s\(^{1}\)2s\(^{2}\)2px\(^{1}\)2py\(^{1}\)
View Answer & Discuss WAEC 2022
14

Which of the following properties indicate that an element is a metal. It

I. reacts with oxygen to form an acidic oxide
II. forms ionic chlorides
III. has variable oxidation states
IV. displaces hydrogen from dilute HCl

  • A. I and III only
  • B. I and II only
  • C. II and IV only
  • D. I, II, III and IV
View Answer & Discuss WAEC 2022
15

Ionization energy increases across the period in the periodic table because

  • A. atomic number increases
  • B. effective nuclear charge increases
  • C. mass number decreases
  • D. screening effect decreases
View Answer & Discuss WAEC 2022
16

The IUPAC name of the compound CH3CH(CH3)CHCH2 is

  • A. 2 - methyl but - 1 - ene
  • B. 2 - methyl but - 2 - ene
  • C. 3 - methyl but - 1 - ene
  • D. 3 - methyl but - 2 - ene
View Answer & Discuss WAEC 2022
17

The maximum number of covalent bonds formed by nitrogen is

  • A. 1
  • B. 2
  • C. 3
  • D. 4
View Answer & Discuss WAEC 2022
18

Which of the following bond types is intermolecular?

  • A. Covalent bond
  • B. Hydrogen bond
  • C. Ionic bond
  • D. Metallic bond
View Answer & Discuss WAEC 2022
19

What is the percentage composition of carbon
in Ca(HCO3)\(_{2}\) ?
[ Ca = 40.0, 0= 16.0, C = 12.0, H= 1.0]

  • A. 22.2%
  • B. 14.8%
  • C. 7.4%
  • D. 3.7%
View Answer & Discuss WAEC 2022
20

Which of the following elements would displace copper from a solution of copper ions?

  • A. silver
  • B. gold
  • C. lead
  • D. mercury
View Answer & Discuss WAEC 2022
21

If 50 cm\(^{3}\) of a saturated solution of KNO\(_{3}\) at 40 Β°C contained 5.05 g of the salt, its solubility at the same temperature would be
[KNO\(_{3}\) = 101]

  • A. 1.0 mol dm\(^{-3}\)
  • B. 1.5 mol dm\(^{-3}\)
  • C. 2.0 mol dm\(^{-3}\)
  • D. 5.0 mol dm\(^{-3}\)
View Answer & Discuss WAEC 2022