1992 - WAEC Chemistry Past Questions & Answers - page 1

1
When steam is passed over white-hot coke, the products are
A
carbon (IV) oxide and nitrogen
B
carbon (IV) oxide and hydrogen
C
carbon (ll) oxide and nitrogen
D
carbon (lV) oxide and steam
CORRECT OPTION: b
2
The maximum number of electrons that can accommodated in the shell having the principal quantum number 3 is
A
3
B
9
C
10
D
18
CORRECT OPTION: d
3
Methanol is obtained from wood by
A
esterification
B
bacterial decomposition
C
combustion
D
fractional distillation
CORRECT OPTION: e
4
Study carefully the reaction represented by the equation below. 2H2O 2(l) → O 2(g) + 2H2O(l). Which of the following will not reaction increase the reaction rate?
A
Heating the hydrogen peroxide
B
Adding a pinch of MnO2 to the reactant
C
increasing the concentration of the H2O2
D
Adding water to the reactant
CORRECT OPTION: d
5
Which of the following processes is a physical reaction?
A
Electrolysis
B
Hydrolysis
C
Allotropic change
D
Neutralization
CORRECT OPTION: c
6
If the volume of a given mass of gas at 298 K and pressure of 205.2 x 103 Nm-2 is 2.12dm3, what is volume of the gas at s.t.p? (Standard pressure = 101.3 x 103 Nm-2, Standard temperature = 273K)
A
39.3dm 3
B
22.4dm3
C
4.93dm3
D
3.93dm3
CORRECT OPTION: d
7
The following acids are monobasic except
A
methanoic acid
B
dioxonitrate lll acid
C
ethanedioic acid
D
oxochlorate (l) acid
CORRECT OPTION: c
8
The reactions ethyne are mainly
A
substitution reactions
B
addition reactions
C
addition polymerization
D
catalytic hydrogenation
CORRECT OPTION: b
9
When air is passed through potash and then pyrogallol, the components are noble gases,
A
oxygen and carbon (IV) oxide
B
oxygen and nitrogen
C
nitrogen and water vapour
D
water vapour and carbon (IV) oxide
CORRECT OPTION: c
10
The halide used widely in photography is
A
ammonium chloride
B
calcum chloride
C
silver bromide
D
sodium brmide
CORRECT OPTION: c
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