1994 - WAEC Chemistry Past Questions & Answers - page 1

1
The components of universal indicator solution can best be separated by
A
chromatography
B
filtration
C
evaporation
D
crystallization
CORRECT OPTION: a
2
The number of replaceable hydrogen atoms in one acid indicates its
A
basicity
B
acidity
C
alkalinity
D
reactivity
CORRECT OPTION: a
3

Catalytic hydrogenation of alkenes produces compounds with the general formula

A
CnH2n+1 OH
B
CnH2n+1
C
CnH2n+2
D
CnH2n-2
CORRECT OPTION: c

.In a hydrogenation reaction, two hydrogen atoms are added across the double bond of an alkene, resulting in a saturated .

4
A measure of the degree of disorder in a chemical system is known as the
A
enthalpy
B
free energy
C
activation energy
D
entrophy
CORRECT OPTION: d
5
In any chemical reaction, the total mass of the products is always equal to that of the reactants. This is statement of the law of
A
definite proportion
B
conservation of matter
C
multiple proportions
D
reciprocal proportions
CORRECT OPTION: b
6
Which of the following is not a property of magnesium oxide?
A
High melting point
B
Dissolution in polar solvents
C
Presence of ionic bonds
D
Possession of crystal lattice
CORRECT OPTION: e
7
Which of the following would increase the rate of reaction of chips of a metal M as shown in the equation below? M(s) + 2HCI(aq) → MCI2(aq) + H2(g)
A
Diluting the hydrochloric acid
B
Adding some distilled water
C
Decreasing the temperature
D
Grinding the metal into powder
CORRECT OPTION: d
8
The oxidation number of phosphorus in PO 3/4 is
A
+ 1
B
+2
C
+3
D
+4
CORRECT OPTION: e
9
The number of atoms in 1.2g of carbon - 12 isotope is
A
1.00 x 10 22
B
6.02 x 1022
C
1.20 x 10 23
D
1.00 x 1023
CORRECT OPTION: b
10
Tetraoxosulphate (lV) acid is described as strong acid because it is highly
A
corrosive
B
concentrated
C
reactive
D
soluble in water
CORRECT OPTION: e
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