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.
To what temperature must a gas be raised from 273K in order to double both its volume and pressure?``
A298k
B300k
C546k
D819k
E1092k
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Question 1802
waec1990
Which of the following is not correct of glucose and fructose?They
Aare structural isomers
Breduce fehling's solution
Ccan be obtained by the hydrolysis of starch
Dare readily fermented by enzymes
Eare soluble in water
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Question 1803
waec1990
Which of the following statements explains why tetraoxosulphate (IV) acid is reqarded as a strong acid?
ATetraoxosulphate (IV) acid is dibasic
Bthe acid is concentrated
Cthe acid is complately ionized in aqueous solution
Dtetraxosulphate (IV) ions are very reactive
Ethe acid is highly corrosive
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Question 1804
waec1990
How many mole of AgNO\(_3\) are there in 500cm\(^3\) of 0.01M AgNO\(_3\) solution?
A0.005 mole
B0.05 mole
C0.5 mole
D5 moles
E1 mole
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Question 1805
waec1990
The following alloys contain copper except
Amagnalium
Bduralumn
Cbronze
Dbrass
Etype metal
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Question 1806
waec1990
Which of the following equations represents the reaction leading to the removal of permanent hardness of water?
ACa(HCO 3)2 → CaCO3 + H2O + CO2
BMgSO4 + Na 2CO3 + Na 2SO
CCa(OH) 2 + 2HCI → CaCI 2 + 2H 2O
DCa(HCO3)2 + Ca(OH)3 → 2CaCO3 + 2H2O
EMgSO4 + BaCI2 → MgCI2 + BaSO4
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Question 1807
waec1990
In the reaction represented by the equation; 2FeCI3 + SO2 + 2H2O → 2FeCL2 + H2SO4 + 2HCI the oxidation number of sulphur changes from
A+2 to + 6
B+ 4 to + 6
C0 to + 6
D- 2 to + 4
E+2 to + 4
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Question 1808
waec1990
Which of the following pollutants is biodegradable ?
ASewage
BPlastics
CMetal scrape
DLead compounds
EHydrogen sulphide
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Question 1809
waec1990
MO and X 2O represent the formula of oxides of elements M and X respectively . If M and X should combine to form a separate compound, what would be the formula of the compound?
AMX2
BM2X
CMX
DM3X2
EMX3
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Question 1810
waec1990
What is the molecular formula of a compound whose empirical formula is CH2O and molar mass is 180? (H = 1, C = 12, O = 16)
AC 4H 8O2
BC 4H 8O3
CC 6H 10O5
DC 6H 12O6
EC 12H 22O11
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Question 1811
waec1990
The compound of copper which is used in electroplating dyeing, printing, wood preservation and as a fungicide is
Acopper (ll) hydroxide
Bcopper (ll) trioxonitrate (V) pentahydrate
Ccopper (ll) tetraoxosulphate (VI) pentahydrate
Dcopper (ll) oxide
Ecopper (ll) trioxocarbonate (lV)
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Question 1812
waec1990
Which of the following salts in aqueous solution will have a pH greater than 7?
ANaCl
BACI3
CFeCI3
DNa 2SO4
EK 2CO3
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Question 1813
waec1990
The gas that is liberated when iron is heated with concentrated tetraoxosulphate (VI)acid is
AH2S
B\(SO_{2}\)
CHCI
DSO3
EO2
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Question 1814
waec1990
Which of the following correctly explains entropy?
Athe natural tendency for a system to achieve a greater disorder
Ba balance of two driving forces between free energy and enthalpy changes
Cthe cause of spontaneity of a reaction
Da measure of the enthalpy of a reaction
Ea measure of the rate of attaining equilibrum in a reversible reaction
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Question 1815
waec1990
How many molecules are there in 14g of nitrogen gas at s.t.p? (n = 14, Avogadro Number = 6. 0 x \(10^{23 }\)mol-1)
A1.2 x 10 23
B3.0 x 1023
C6.0 x1023
D1.2 x 1024
E30 x1023
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Question 1816
waec1990
A catayst which increases the rate of a chemical reaction does so by
Aincreasing the reaction pathway
Bincreasing the surface area of the reactants
Cincreasing the pressure on the system
Ddecreasing the temperature at which the reaction occurs
Edecreasing the activation energy of the reaction
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Question 1817
waec1990
Which of the following reactions does not occur in the blast furnace during the extraction of iron?
AFe2O3(s) + 3CO(g) → 2Fe(l) + 3CO2(g)
BC2 + CO 2(g)
CCaO(s) + SiO2(s) → CaSiO 3(s)
DFeO(s) + CO2(g) + Fe(l)
E2Fe2O(s) → 4Fe(l) 3O2(g)
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Question 1818
waec1990
Which of the following compounds will undergo additional reactions?
AEthyne
BButane
CPentane
DTetrachloromethane
EEthanol
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Question 1819
waec1990
When a solid melts and consequently boils, there is
Aa gradual increase in the average kinetic energy of the particles
Ba sudden decrease in the kinetic energy of the particles
Cno change in the average kinetic energy of the particles
Da rapid change in the nature of bonding of the components
Ea change in the size of the fundamental particles
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Question 1820
waec1990
Aluminum is above iron in the electrochemical series, yet iron corrodes easily on exposure to air while aluminium does not. This is because aluminium
