1991 - WAEC Chemistry Past Questions and Answers - page 2
11
The products of the electrolysis of dilute sodium chlorid solution with platinum electrodes are
A
hydrogen and oxygen
B
oxygen and chlorine
C
chlorine and water
D
sodium amalgam and chlorine
correct option: a
Users' Answers & Comments12
Which of the following modes of motion is exhibited by the particles of a solid?
A
Vibrational and random motion
B
Vibrational and translational motion
C
Translational and random motion
D
Vibrational motion only
correct option: d
The cohesive forces binding the particles of a solid are strong enough to restrict their movement so that they are held together in a fixed point. They only vibrate and rotate about their fixed point.
13
Which of the following statements is not correct? Group 7 elements
A
are diatomic
B
are good oxidizing agents
C
are highly electronegative
D
have relatively low ionization potentials
correct option: d
Users' Answers & Comments14
In which of the following are the substances arranged in their correct order of increasing melting point?
A
Sodium chloride, sulphur, diamond
B
Diamond, sodium chloride, sulphur
C
Sulphur, sodium chloride, diamond
D
Diamond, sulphur, sodium chloride
correct option: c
Users' Answers & Comments15
A compound which liberates carbon (IV) oxide from a hydrogentrioxocarbonate (lV) could have the molecular formula
A
C2H5OH
B
C 3H 4
C
HCOOH
D
H2O2
correct option: c
Users' Answers & Comments16
CH4(g) + 2O2(g) → 2H2O(l) + CO2(g) ∆H = 890KJ mo-1 ∆H in the reaction represented by the equation above is the enthalpy of
A
formation
B
combustion
C
solution
D
activation
correct option: b
Users' Answers & Comments17
Consider the reaction represented by the equation below: H2(g) + 12(s) ⇌ 2HI(g) ∆H negative. Which of the following takes place when the temperature of the reaction vessel is decreased?
A
the gases condense
B
the yield of hydrogen increases
C
the concentration of the reactants remain constant
D
more of the hydrogen iodide decomposes
correct option: e
Users' Answers & Comments18
2NaNO3 → 2NaNO2 + O2. From the equation above, what is the volume of oxygen produced at s.t.p. when 8.5g of 2NaNO3 is heated until no further gas is evolved? (2NaNO3 = 85, molar volume of gases at s.t.p. = 22.4dm3)
A
1.12dm3
B
2.24dm3
C
4.48dm3
D
11.2dm3
correct option: a
Users' Answers & Comments19
Esterification of propane 1,2,3-triol and unsaturated higher carboxylic acids will produce
A
fats
B
soap
C
methly-propanoate
D
alkanols
correct option: c
Users' Answers & Comments20
The ratio of reactants to products is 1: 3: 2 in the reaction represented by the equation below: N2,/SUB> (g) → 2NH3(g) which of the following law is demonstrated by this?
A
Boyle's law
B
Law of multiple proportion
C
Gay Lussac's law
D
Law of constant composition
correct option: c
Users' Answers & Comments