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The colour of phenolphthalein indicator in dilute HNO
Acolourless
Borange
Cpink
Dpurple
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Question 13
waec2008
Which of the following set of equations could be used to represent the standard enthalpy of formation of glucose?
A6C (s) + 6H 2(g) + 3O2(g) → C 6H12O6(s)
B6CO2(g) + 6H2O (l) → C6H12O6(s) + 6O 2(g)
C6C(g) + 6H 2(g) + 3O2(g) → C6H12O 6(s)
D6C(g) + 6H 2(g) + 3O2(g) → C 6H 12O 6(aq)
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Question 14
waec2008
Diamond does not conduct electricity because it?
Ahas no free valence electrons
Bis a giant molecule
Ccontains no bonded electrons
Dis a solid at room temperature
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Question 15
waec2008
The collision theory proposes that
Areactants collide more frequently to bring about reduction in the reaction rate
Ball collisions of reactants are effective
Creactants must collide with a certain minimum amount of energy to from products
Dthe fewer the collisions the faster the reaction rate
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Question 16
waec2008
When concentrated \(H_2SO_4\) is added to NaCI (s), the gas evolved
Ableaches damp blue litmus paper
Bforms a white preciptate with AgNO3(aq)
Cforms a white precipitate with BaCI2(aq)
Dturns moist red litmus paper blue
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Question 17
waec2008
In a fixed volume of a gas, an increase in temperature results in an increase in pressure due to an increase in the
Anumber of the collisions between the gas molecules and the walls of the container
Bkinetic energy of the gas
Cnumber of collisions between the gas molecules
Dnumber of repulsion between the gas molecules
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Question 18
waec2008
Which of the following gases has the lowerst rate of diffusion under the same conditions of temperature and pressure? [H = 1, O = 16, Ne = 20, CI = 35]
AChlorine
BHydrogen
CNeon
DOxygen
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Question 19
waec2008
Consider the reaction represented by the following equation: Zn(s) + 2HCI(aq) → ZnCI2(aq) + H2(g) what volume of hydrogen gas is produced at s.t.p. when 3.25 g of zinc reacts with excess dilute HCI? [Zn = 65, Molar gas volume at s.t.p. = 22.4 dm-3]
A1.12 dm3
B2.24dm3
C4.48dm3
D8.96dm3
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Question 20
waec2008
If 5.00cm3 of 0.20 mol dm-3Na2CO3 was diluted with distilled water to obtain 250 cm3 solution, what is the concentration of the resulting solution?
A0.004 mol dm-3
B0.02 mol dm-3
C0.20mol dm-3
D0.40mol dm-3
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Question 21
waec2008
Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N = 14]
ANH3 = 17
BNH4CI = 53.5
CNH4NO3 = 80
D(NH3)2SO4 = 132
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Question 22
waec2008
Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N = 14]
ANH3 = 17
BNH4CI = 53.5
CNH4NO3 = 80
D(NH3)2SO4 = 132
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Question 23
waec2008
What is the mass of 6.02 x 1024 atoms of magnesium? [Mg = 24, Avogadro c x 1023 atoms mol-1]
A240g
B24 g
C2.4g
D0.24g
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Question 24
waec2008
The force of attraction between covalent molecules is?
Aelectrostatic attraction
Bhydrogen bonding
Cionic force
Dvan der Waals forces
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Question 25
waec2008
Water molecules are held together by
Acovalent bond
Bhydrogen bond
Cionic forces
Dvan der Waals forces
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Question 26
waec2008
Arrange the following elements in order of increasing electron affinity: Br2CI2
I 2
F 2
AI 2CI2Br2F 2
BI 2Br2CI2F 2
CCI2 I 2Br2F 2
DBr2CI2 I 2 F 2
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Question 27
waec2008
Consider the following elements and their electronic configurations
W: 1s22s2
X: 1s 22s22p6
Y: 1s22s22p63s2
Z: 1s22s22p63s23p2. Which of the elements belong to the same group in the periodic table?
AW and X only
BY and Z only
CW and Y only
DW, Y and Z only
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Question 28
waec2008
Elements in the same group of the periodic table have
Athe same number of valence electrons
Bthe same number of electron shells
Cdifferent chemical behaviour
Dthe same atomic size
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Question 29
waec2008
Which of the following statements is not true of halogens?
Athey exist in different physical states
Bthey exist as diatomic molecules
Ctheir ionic radii decrease down the group
Dtheir melting and bolling points increase down the group
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Question 30
waec2008
Atom \(^{234} _{88} Q\) decay by alpha emission to give an atom R. The atomic number and mass number of atom R are respectively
