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8.0 g of an element X react with an excess of copper (ll) tetraoxosulphate (lV) solution to deposit 21.3 g of copper. The correct equation for the reaction is?
(Cu = 64).
AX(s) + CuSO4(aq) → Cu(s) + XSO4(aq)
BX(s) + 2CuSO4(aq) → 2Cu(s) + X(SO4)2(aq)
C2X(s) + CuSO4(aq) → Cu(s) + X2SO4(aq)
D2X(s) + 3CuSO4(aq) → 3Cu(s) + X2(SO4)3(aq)
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Question 1522
jamb1998
A given amount of gas occupies 10.0 dm3 at 4atm and 273°C. The number of moles of the gas present is?
(Molar volume of a gas at s.t.p. = 22.4 dm3)
A0.89 mol
B1.90 mol
C3.80 mol
D5.70 mol
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Question 1523
jamb1998
A mixture of iron and sulphur can be separated by dissolving the mixture in?
Asteam
Bdilute hydrochloric acid
Cdilute sodium hydroxide
Dbenzene
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Question 1524
jamb1998
The addition of water to calcium oxide leads to?
Aa physical change
Ba chemical change
Cthe formation of a mixture
Dan endothermic change
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Question 1525
waec1997
What is the basicity of the acid in the followed reaction? NaCO + 2CHCOOH → 2CH COONa + H2O + CO2
A1
B2
C3
D4
E8
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Question 1526
waec1997
A mixture of NaCI(s) and CaCO3(s) is best separated by
Adissolution followed by filtration
Bsublimation followed by crystallization
Cdissolution followed by evaporation
Ddissolution followed by crystallization
Esublimation followed by dissolution
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Question 1527
waec1997
What volume of oxygen at s.t.p would react with carbon to form 4.40g of CO2 according to the following equation? C(s) + O2(g) → CO2(g) [O = 16; C =12; 1 mole of a gas occupies 22.4dm3 at s.t.p]
A0.224dm3
B2.24dm3
C4.40dm3
D4.48dm3
E22.4dm3
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Question 1528
waec1997
Boyle's law can be expressed mathematically as
AV \(\alpha\) T (P constant)
BP \(\alpha\) V (T constant)
CP \(\alpha\) T
DV \(\alpha\) 1 / p(T constant)
EV1/T1 = / T2
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Question 1529
waec1997
Which of the following Group 1 elements has the highest ionization energy?
A55Cs
B37Rb
C19K
D11Na
E3Li
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Question 1530
waec1997
Which of the following statements is correct about sodium chloride in the solid state?
Ait exists as aggregates of ions
Bit conducts electricity
Cits melting point is below 100oC
Dit exists as discrete molecules
Eits ions are linked by metallic bonds
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Question 1531
waec1997
The valence electrons of element 12Mg are in the
A1s orbital
B2s orbital
C2px orbital
D2py orbital
E3s orbital
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Question 1532
waec1997
Element X, with electronic configuration 2, 8, 2 and element Y with electronic configuration 2, 8, 7 are like to combine by
Ametallic bonding
Bcovalent bonding
Celectrovalent bonding
Ddative bonding
Ehydrogen bonding
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Question 1533
waec1997
If an element R belongs to the same group as sodium, an aqueous solution of ROH will
Abe neutral
Bbe acidic
Cbe coloured
Dhave pH greater than 7
Eturn back litmus red
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Question 1534
waec1997
An atom 17 protons, 17 electrons and 18 neutrons has a mass number of
A17
B18
C34
D35
E52
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Question 1535
waec1997
Lead and tin are the components of
Asteel
Bbronze
Cbrass
Ddentist amalgam
Esoft solder
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Question 1536
waec1997
Which of the following is an ore of aluminium?
AHaematite
BMagnetite
CSiderite
DBauxite
ECassiterite
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Question 1537
waec1997
Which of the following metals is not extracted by electrolysis ?
Alron
BSodium
CCalcium
DMagnesium
EAluminium
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Question 1538
waec1997
The following oxides react with both acids and bases to form salts except
Azinc oxide
Blead (ll) oxide
Caluminium oxide
Dtin (IV) oxide
Ecarbon (Iv) oxide
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Question 1539
waec1997
Which of the following is used as water softener?
ANa2CO3.10H2O
BCuSO4. 5H2O
CMgSO4. 7H2O
DCaCI2.2H2O
ENa2SO4. 10H2O
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Question 1540
waec1997
Which of the following when heated strongly in air will leave a metal as residue?
