Chemistry JAMB, WAEC, NECO AND NABTEB Official Past Questions

2101

Arrange the following elements in order of increasing electron affinity: Br2CI2
I 2
F 2

  • A. I 2CI2Br2F 2
  • B. I 2Br2CI2F 2
  • C. CI2 I 2Br2F 2
  • D. Br2CI2 I 2 F 2
View Answer & Discuss WAEC 2008
2102

Consider the following elements and their electronic configurations
W: 1s22s2
X: 1s 22s22p6
Y: 1s22s22p63s2
Z: 1s22s22p63s23p2. Which of the elements belong to the same group in the periodic table?

  • A. W and X only
  • B. Y and Z only
  • C. W and Y only
  • D. W, Y and Z only
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2103

Elements in the same group of the periodic table have

  • A. the same number of valence electrons
  • B. the same number of electron shells
  • C. different chemical behaviour
  • D. the same atomic size
View Answer & Discuss WAEC 2008
2104

Which of the following statements is not true of halogens?

  • A. they exist in different physical states
  • B. they exist as diatomic molecules
  • C. their ionic radii decrease down the group
  • D. their melting and bolling points increase down the group
View Answer & Discuss WAEC 2008
2105

Atom \(^{234} _{88} Q\) decay by alpha emission to give an atom R. The atomic number and mass number of atom R are respectively

  • A. 86 and 230
  • B. 87 and 234
  • C. 88 and 233
  • D. 90 and 238
View Answer & Discuss WAEC 2008
2106

What is the atomic number of an element whose cation Y+ has the electronic configuration 1s22s22p6?

  • A. 9
  • B. 10
  • C. 11
  • D. 12
View Answer & Discuss WAEC 2008
2107

The valence electrons in a chloride ion are [17CI]

  • A. 2p electrons only
  • B. 3s and 3p electrons only
  • C. 3p and 3d electrons only
  • D. 3p electrons only
View Answer & Discuss WAEC 2008
2108

Find the number of neutrons in an atom represented by 4521X.

  • A. 21
  • B. 24
  • C. 45
  • D. 66
View Answer & Discuss WAEC 2008
2109

The mass spectrometer can be used to measure mass of

  • A. an atom
  • B. an electron
  • C. a proton
  • D. a neutron
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2110

Which of the these metals will not liberate hydrogen from dilute HCI?

  • A. Copper
  • B. Iron
  • C. Magnesium
  • D. Zinc
View Answer & Discuss WAEC 2007
2111

What volume will 0.5 g of H2 occupy at s.t.p? [H = 1; 1 mole of a gas occupy 22.4 dm3 at s.t.p.]

  • A. 2.24 dm3
  • B. 5.60dm3
  • C. 11.20dm3
  • D. 44.80dm3
View Answer & Discuss WAEC 2007
2112

Pig-iron is brittle because it contains

  • A. a high percentage of carbon as impurity
  • B. calcium trioxosilicate (IV)
  • C. unreacted haematite
  • D. undecomposed limestone
View Answer & Discuss WAEC 2007
2113

The following substances are heavy chemicals except

  • A. sodium trioxocarbonate (IV)
  • B. tetraoxosulphate (VI) acid
  • C. lead (lV) tetraethyl
  • D. sodium hydroxide
View Answer & Discuss WAEC 2007
2114

Which of the following methods can be used to separate a mixture of two miscible liquids with different boiling points?

  • A. Decantation
  • B. Distillation
  • C. Evaporation
  • D. Filtration
View Answer & Discuss WAEC 2007
2115

from the following ores is iron extracted? I. Haematite ll. Bauxite III. Magnetite IV. Cassiterite

  • A. l and ll only
  • B. l and lll only
  • C. l, ll and lll only
  • D. l, ll, lll and lV
View Answer & Discuss WAEC 2007
2116

Glucose reduces Fehling’s solution on warming to

  • A. copper (l) oxide
  • B. copper (ll) oxide
  • C. copper (l) chloride
  • D. copper (ll) hydroxide
View Answer & Discuss WAEC 2007
2117

Which of the following compounds reacts readily with sodium to liberate hydrogen?

  • A. CH3CH2CH3
  • B. CH3COOH
  • C. CH3 CH2CHO
  • D. CH3 CH(OH)CH3
View Answer & Discuss WAEC 2007
2118

Consider the reaction below: Vegetable oil \(\frac{H2;NI catalyst}{High temperature}\) product. The reaction is applied in the manufacture of?

  • A. drugs
  • B. margarine
  • C. paraffin wax
  • D. soapy detergents
View Answer & Discuss WAEC 2007
2119

Hydrocarbons which react with ammoniacal copper (l) chloride solution conform to the general molecular formula

  • A. CnH2n
  • B. CnH2n
  • C. CnH2n+2
  • D. CnH2n-2
View Answer & Discuss WAEC 2007
2120

Alkenes undergo the following reactions except

  • A. addition
  • B. hydration
  • C. polymerization
  • D. substitution
View Answer & Discuss WAEC 2007
2121

Which of the following pairs of substances can be distinguished by use of NaHCO3 solution?

  • A. CH 3CH2OH and HCOOCH3
  • B. CH 3CH2OH and CH3COOH
  • C. CH3COOH and HCOOH
  • D. CH 3CH2OH and CH3OH
View Answer & Discuss WAEC 2007