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The following metals are extracted by the electrolytic method except
Apotassium
Bcalcium
Csodium
Dtin
Emagnesium
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Question 762
waec1990
Which of the following compounds crystallizes without water of crystallization?
ANa2CO3
BCuSO4
CMgSO4
DNaCI
EFeSO4
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Question 763
waec1990
The decomposition of hydrogen peroxide is represented by the equation: 2H2O(l) + O2(g) what mass of hydrogen peroxide would be required to produce 22.4dm3 of oxygen at s.t.p? (H = 1, O = 16, molar volume of a gas at s.t.p. = 22.4dm3)
A18 g
B34 g
C36 g
D64 g
E68 g
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Question 764
waec1990
Nuclear reactions can be used in the following except
Agauging the thickness of objects
Bmaking atomic bombs
Ccuring cancer
Dgenerating electricity
Epurifying water
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Question 765
waec1990
Which of the following is normally used for drying ammonia gas?
AConcentrated tetraoxonitrate (Vl) acid
BCalcium oxide
Canhydrous calcium chloride
Dphosphorus (V) oxide
Eanhydrous copper (ll) tetraoxosulphate (VI)
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Question 766
waec1990
Which of the following explains why trioxonitrate (V) acid is not used for preparing hydrogen from metals?
Ait is volatile
Bit is strongly oxidizing
Cit forms a layer of oxide on the metal
Dtrioxonitrate (V) salts are soluble in water
Eit renders the metals passive
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Question 767
waec1990
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 768
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 769
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 770
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 771
waec1990
The following alloys contain copper except
Amagnalium
Bduralumn
Cbronze
Dbrass
Etype metal
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Question 772
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 773
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 774
waec1990
Which of the following pollutants is biodegradable ?
ASewage
BPlastics
CMetal scrape
DLead compounds
EHydrogen sulphide
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Question 775
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 776
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 777
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 778
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 779
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 780
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
