1997 - WAEC Chemistry Past Questions and Answers - page 3
21
How much heat will be liberated if 8g of hydrogen burns in excess oxygen according to the following equation? 2H2 + O2→ 2H2O,∆H = -571.7KJ (H = 1)
A
1.42.9KJ
B
571.7KJ
C
1143.4KJ
D
285.9KJ
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22
The position of equilibrium in a reversible reaction is affected by
A
particle size of the reactants
B
change in concentration of the reactants
C
change in size of the reaction vessel
D
vigorous stirring of the reaction mixture
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23
Separation of mixture of solids by physical methods can be based on differences in the following except
A
melting point
B
solubility
C
particle size
D
molar mass
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24
Ethene undergoes mainly addition reactions because it is
A
a gas
B
a hydrocarbon
C
unsaturated
D
easily polymerized
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25
The reaction between alkanoic acids and alkanols in the presence of a mineral acid is known as
A
saponification
B
hydrolysis
C
polymerization
D
esterification
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26
Which of the following is the relative molecular mass of a compound which has empirical formula CH\(_2\)O? (H = 1; C = 12; O = 16)
A
42
B
45
C
126
D
180
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27
The by-product of the fermentation of sugar to ethanol is
A
propane -1,2,3-triol
B
ethyl ethanoate
C
ethanedioc acid
D
propanol
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28
Alkanes react with the halogens mainly by
A
oxidation
B
polymerization
C
addition
D
reduction
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29
Which of the following is used widely in the manufacture of flavours and perfumes?
A
Alkanoates
B
Alkanones
C
Alkanes
D
Complex sugars
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30
The use of diamond in abrasives is due ti its
A
high melting point
B
durability
C
lustre
D
hardness
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