1999 - WAEC Chemistry Past Questions and Answers - page 2
11
The crystal layers in graphite are held together by
A
electrostatic forces
B
van der Waals' forces
C
hydrogen bonds
D
covalent bonds
correct option: d
Users' Answers & Comments12
Which of the following compounds has the highest ionic character?
A
PCI5
B
SiCI4
C
AICI3
D
KCI
correct option: d
Users' Answers & Comments13
If an element with high electron affinity combines with another element with low ionization energy the bond formed will be mainly
A
covalent
B
ionic
C
dative
D
metallic
correct option: b
Users' Answers & Comments14
One mole of a compound M(HCO3)2 has a mass of 162g. Calculate the relative atomic mass of M. [H = 1, C =12, O = 16]
A
122
B
101
C
53
D
40
correct option: d
One of the mole of M(HCO3)2 = 162g; M +(1 + 12 + 16 x 3) x 2 = 162; M +122 = 162,:. M = 162 - 122 = 40g
Users' Answers & Comments15
Exhaust fumes discharged from a smoky vehicle gradually become invisible as a result of
A
diffusion
B
combustion
C
absorption
D
emission
correct option: a
Users' Answers & Comments16
Which of the following movements can be described as random motion?
A
wheelbarrow being pushed
B
car travelling on a straight line
C
Gas molecules colliding in a flask
D
Planets going round the sun
correct option: c
Users' Answers & Comments17
Equal volumes of CO2 cnd CO at s.t.p have the same
A
mass
B
density
C
rate of diffusion
D
number of molecules
correct option: d
Users' Answers & Comments18
Gas molecules are said to be perfectly elastic because
A
they collide without loss of energy
B
they move about in straight lines
C
the distances between them are negligible
D
the volume occupied by them is negligible
correct option: a
Users' Answers & Comments19
What volume of hydrogen is produced at s.t.p. When 2.60 g of zinc reacts with excess HCI according to the following equation? Zn(s) + 2HCI(aq) → ZnCI 2(aq) + H2(g) [Zn = 65; 1 mole of a gas occupies 22.4dm3 at s.t.p]
A
0.040dm 3
B
0.896dm 3
C
5.82dm 3
D
8.62dm 3
correct option: b
Zn + 2HCI → ZnCI2 + H2; 65g of Zn produces 22.4 dm3 of H2; .: 2.6g of Zn will produce = 2.6/65 x 22.4 = 0.896 dm3
Users' Answers & Comments20
Helium is preferred to hydrogen in filling balloons because hydrogen
A
is inflammable
B
is diatomic
C
exhibits isotopy
D
is a component of water
correct option: a
Users' Answers & Comments