1992 - WAEC Chemistry Past Questions and Answers - page 2
11
The scum formed when soap is mixed with hard water could be
A
calcium trioxocarbonate (IV)
B
propane- 1, 2, 3 - triol
C
calcium hydrogentrioxocarbonate (IV)
D
magnesium tetraoxosulphate (IV)
correct option: a
Users' Answers & Comments12
What is the quantity of electricity produced when a current of 0.5A is passed for 5 hours 45 mins? (1F = 96500C)
A
0. 11F
B
0.12F
C
0.22F
D
1.1F
correct option: a
Users' Answers & Comments13
''The rate a reaction is proportional to the number of effective collisions occurring per second between the reactants''. This statement is associated with the
A
Kinetic theory
B
rate law
C
atomic theory
D
collision theory
correct option: d
Users' Answers & Comments14
What is the following compounds will not decompose when heated strongly ?
A
NaHCO3
B
K2CO3
C
MgCO3
D
Ca(HCO3)2
correct option: b
Users' Answers & Comments15
What is the change in the oxidation number of phosphorus in the the reaction represented by the following equation? 4P (s) + 5O(2)(g) → 2P2O5(g)
A
0 to + 2
B
0 to 5
C
+4 to + 2
D
+4 to +5
correct option: b
Users' Answers & Comments16
When iron rusts, it undergoes
A
deliquescence
B
chemical decomposition
C
hydrolysis
D
redox reaction
correct option: d
Users' Answers & Comments17
Consider the compounds represented by the following general formula: X2SO4 Y2(SO4)3, 24H2OX and Y could respectively be
A
K and AI
B
Fe and K
C
AI and Fe
D
AI and K
correct option: a
Users' Answers & Comments18
Which of the following involves the decomposition enzymic action?
A
Esterification
B
Fermentation
C
Dehydration
D
Polymerization
correct option: b
Users' Answers & Comments19
The following salts are readily soluble in water except
A
Na2CO3
B
Pb(NO3)2
C
KCI
D
CuCO3
correct option: e
Users' Answers & Comments20
When sucrose is warmed with Fehling's solution
A
a silver mirror is produced
B
the solution turns milky
C
a brick-red precipitate is formed
D
there is no precipitate
correct option: d
Users' Answers & Comments