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What product is formed at the cathode during the electrolysis of concentrated sodium chloride solution using carbon electrodes?
AChlorine
BHydrogen
COxygen
DSodium
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Question 442
waec2007
What is the oxidation number of chromium in K2CrO4?
A+1
B+2
C+4
D+6
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Question 443
waec2007
Which of these cell notations is the correct representation of a Daniell cell?
AZn(s) / Zn2+(aq) // Cu2+(aq)/Cu(s)
BCu(s) / CU2+(aq) // Zn2+(aq) / Zn(s)
CZn2+(aq) / Zn(s) // Cu2+(aq) /Cu(s)
DCu2+(aq) / Cu(s) // Zn(s) / Zn2+(aq)
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Question 444
waec2007
Consider the reaction represented by the following equation: N2(g) + 3H2(g) ⇌ 2NH3(g); ∆H = - 92kJmol1. Finely divided iron is used as catalyst in the reaction in order to
Alower the value of ∆H
Bincrease the time for attainment of equilibrium
Cshorten the time for attainment of equilibrium
Ddecrease the yield of ammonia
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Question 445
waec2007
A solution of a salt X reacts with AgNO3 solution to give white precipitate which dissolves in excess aqueous ammonia. X contains
ACI-
BPb 2+
CSO 2-
DZn2+
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Question 446
waec2007
What process is illustrated below? S(s) ⇌H2O⇌ S (aq)
ADecomposition of a solid
BMelting of a solid
CFormation of saturated solution of a solid
DSublimation of a solid
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Question 447
waec2007
Which of the following compounds is a basic salt?
AMg(NO3)2
B(NH4)2SO4
CK4Fe(CN)6
DZn(OH)CI
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Question 448
waec2007
Consider the reaction represented by the equation: Ca(OH)2(aq) + CO 2(g) → CaCO3(s) + H 2O(l)
in the reaction above, CO 2 acts as
Aan acidic oxide
Ban oxidizing agent
Ca basic oxide
Da dehydrating agent
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Question 449
waec2007
In which of the following compound (s) will heat be absorbed on adding water?
l. KNO\(_3\) II. Concentrated H\(_2\)SO\(_4\) III. NH\(_4\)CI
AI only
Blll only
Cl and lll only
Dll and lll only
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Question 450
waec2007
Which of the following statements is true of the molecules of a gas under ideal conditions? The molecules
Amove at random
Bundergo inelastic collisions
Cattract each other
Doccupy a large volume
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Question 451
waec2007
Which of the following gases is light than air?
ACO2
BSO2
CHCI
DNH3
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Question 452
waec2007
When air is successively passed through sodium hydroxide solution, alkaline pyrogallol and then concentrated tetraoxosulphate (VI) acid, its remaining components are
Aoxygen and water vapour
Boxygen and nitrogen
Ccarbon (IV) acid and noble gases
Dnitrogen and noble gases
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Question 453
waec2007
What is the IUPAC name of the compound represented by the molecular formula NaCIO4?
ASodium tetraoxochlorate (l)
BSodium tetraoxochlorate (IV)
CSodium tetraoxochlorate (VI)
DSodium tetraoxochlorate(VII)
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Question 454
waec2007
How many atoms are there in one mole of hydrogen gas? [Avogadro's c x 1023mol-1]
A1.2 x 10 23
B6.0 x 10 23
C1.2 x10 24
D6.0 x 10 24
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Question 455
waec2007
14.8 g of a salt (z)dissolved in 250 cm3 of distilled water gives a concentration of 0.80 mol dm-3. Calculate the molar mass of the salt (z).
A13.5 g mol-1
B18.5 g mol-1
C47.4 g mol-1
D74.0 g mol-1
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Question 456
waec2007
Which of the following species does not contain a co-ordinate bond?
AAI2CI6
BCCI4
CH3O+
DNH +4
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Question 457
waec2007
Which of the following compounds has hydrogen bonds between its molecules?
AHF
BHBr
CHCI
DHI.
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Question 458
waec2007
If the difference between the electronegativities of two elements is large, the type of bond that can be formed between them is
Acovalent
Bdative
Cionic
Dmetallic
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Question 459
waec2007
Which of the following statements about sodium is not true?
ANa+ is smaller in size than Na
BNa is smaller in size than Na+
CNa+ has fewer electrons than Na
DThe effective nuclear charge in Na+ is greater than in Na
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Question 460
waec2007
Which of the following properties of atoms generally increases down a group in the periodic table?
