Study and practice Chemistry past questions with answers and detailed explanations. Then test your knowledge using our interactive CBT practice platform and prepare confidently for your upcoming examinations.
The volume occupied by a given mass of gas depends on its
Adiffusion rate
Btemperature and pressure
Cdegree of solubility
Drelative density
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Question 482
waec2005
Which of the following molecules has a linear structure?
ANH3
BH2O
CCO2
DCH4
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Question 483
waec2005
Which of the following can be used to predict the type of bonding in HCI?
ApH value
BElectronegativity difference
CHeat of neutralization
DHeat of solution
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Question 484
waec2005
An element which can exist in two or more forms in the same physical state, exhibits
Aisotopy
Bstructural isomerism
Callotropy
Dvariable valency
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Question 485
waec2005
An element X has an atomic number of 16. What is its most likely oxidation state in its binary compounds?
A-3
B-2
C+2
D+4
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Question 486
waec2005
Which of the following changes is characteristic of an alpha-particle emission?
Athe nucleus loses two protons and two neutrons
Ba proton combines with an electron giving off heat
Cthe nucleus splits into two equal parts
Dfour neutrons are lost
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Question 487
waec2005
Which of the following sets of elements are arranged in order of decreasing atomic size in the Periodic Table?
A6C, 4Be, 7N,8 O
B4Be,6 C,7 N,8 O
C8O, 7 N, 6C, 4Be
D7N, 8O, 6C,4Be
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Question 488
waec2005
What is the mass number of an element having 20 neutrons, 15 protons and 15 electrons?
A15
B30
C35
D50
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Question 489
waec2005
The electronic configuration of an element X is 1s22s 22s63p 2 3p4. It can be deduced that X
ABelongs to group 6 of the Periodic Table
BBelongs to group IV of the Periodic Table
Chas 3 unpaired electrons in its atom
Dhas relative molecular mass of 16
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Question 490
waec2004
Which of the following measures is not suitable for controlling water pollution?
Atreating industrial effluent and domestic sewage before discharge into water
BControlling the use of agrochemicals
Crecycling industrial and agricultural wastes
Dburning industrial and agricultural wastes before discharge into water ways
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Question 491
waec2004
The process of seeding during the extraction of aluminium involves the addition of pure AI(OH)3 crystals in order to
Alower the temperature
Bincrease the concentration
Cfacilitate the precipitation of solid
Dreduce the viscosity of the solution
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Question 492
waec2004
Which of the following pollutants is biodegradable?
ADomestic sewage
BMetal scraps
CRadioactive waste
DPlastic foil
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Question 493
waec2004
Which of the following is required in an experiment to determine the enthalpy of solution of anhydrous CuSO? l. Mass of the anhydrous CuSO 4 II. Volume of water in which the CuSO4 is dissolved lll. lnitial temperature of water lV. Final temperature of the solution
Al and ll only
Blll and IV only
Cll, lll, and IV only
Dl, ll, lll, and IV only
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Question 494
waec2004
What is the product Cx Hy in the following equation? \(C_{10}H_{22}\) → \(C_{8}H_{18}\) + CxHy
Abutene
Boctane
Cethene
Ddecane
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Question 495
waec2004
WHICH OF THE FOLLOWING PETROLEUM FRACTIONS YIELDS VASELINE AND PARAFFIN WAX ON REDISTILLATION?
ADIESEL OIL
BLUBRICATION OIL
CPETROL
DKEROSENE
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Question 496
waec2004
Which of the following reactions will be affected by change in pressure at equilibrium?
AX(g) + Y(g) ⇌ W(g) + Z(g)
BX(g) + 2Y(g) ⇌W(g) + Z(g)
C2X(g) ⇌ W(g) + Z(g)
D2Y(g) ⇌ W(g) + Z(g)
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Question 497
waec2004
The key factor to be considered in siting a chemical industry is
Afavourable climatic conditions
Bthe availability of space to store raw materials
Cits nearness to other industrial establishments
Dits nearness to the source of raw materials
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Question 498
waec2004
What is the change in the oxidation number of 1- in the reaction represented by the following equation? 51 -1(aq) + 6H+(aq) + 1O-3(aq) → 312(g) + 3H2O(l)
A-5 to -3
B-1 to 0
C+ 5 to + 0
D-1 to + 2
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Question 499
waec2004
Which of the following statements is true of an endothermic reaction? I. Heat is absorbed from the surrounding II. The heat content of the products is more than that of the reactants III. The enthalpy change is positive IV. The surrounding is at a lower temperature than the system.
Al only
Bl and ll only
Cl,ll and lll only
Dl, ll, lll and lV
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Question 500
waec2004
The condensation of several amino acid molecules gives
