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What is the value of -14oC on the Kelvin temperature scale?
A259K
B287 K
C287oK
D259oK
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Question 42
waec2009
What is the percentage by weight of calcium in Ca(OCI)2? [Ca = 40, Cl = 35.5, O = 16]
A28.0%
B31.6%
C43.8%
D44.5%
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Question 43
waec2009
Consider the reaction represented by the equation: 2NaHCO3 → Na2CO 3 + H 2O + CO 2. What is the mass of sodium trioxocarbonate (lV) produced by the complete decomposition of 33.6 g of sodium hydrogen trioxocarbonate (IV)? [NaHCO3 = 84, Na2CO3 = 106]
A10.6 g
B16.8 g
C21.2 g
D42.4 g
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Question 44
waec2009
How many molecules are there in 14 g of nitrogen at s.t.p.? [N = 14, Avogadro's c x 10\(^{23}\) mol-1]
A6.02 x 1023
B3.01 x 1023
C8.43 x 1024
D1.20 x 1024
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Question 45
waec2009
The number of particles in one mole of a chemical compound is the
Aatomic number
Bavogadro's number
Cmass number
Doxidation number
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Question 46
waec2009
Which of the following molecules is not linear in shape?
ACO2
BO 2
CNH3
DHCI
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Question 47
waec2009
In bonded atoms, increase in electronegativity difference,
Aincreases polarity
Bdecreases polarity
Chas no effect on polarity
Dbrings the polarity to zero
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Question 48
waec2009
Which of the following arrangements is in order of increasing ionization energy?
AAI, Si, P, S
BSi, AI,S,P
CS,P,Si,AI
DP, Si,S,AI
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Question 49
waec2009
Which of the following properties of covalent compounds is not correct? They
Aare non-electrolytes
Bare mostly gaseous and volatile liquids
Chave low melting point
Dhave high boiling points
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Question 50
waec2009
Which of the statements about the behaviour of the atom is correct?
Aatomic size decreases down the group
Batomic size increases across the period
Canions are smaller than the parent atom
Dcations are smaller than the parent atom
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Question 51
waec2009
An element Q forms a compound QCI5. In which group of the periodic table is Q?
Al
Blll
CV
DVII
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Question 52
waec2009
Which of the following electronic configurations correctly represents an element in period 3 of the periodic table?
A1s2 2s2 2p2
B1s2 2s2 2p6
C1s2 2s2 2p6 3s2 3p4
D1s2 2s2 2p6 3s2 3p6 4s1
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Question 53
waec2009
Which of the following ions is isoelectronic with neon? [\(_3\)Li, \(_9\)F, \(_{10}\)Ne, \(_{17}\)CI,\(_{19}\)K ]
ACI-
BF-
CK+
DLi,+
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Question 54
waec2009
The following properties are characteristics of transition elements except
Aformation of complex ions
Bfixed oxidation states
Cformation of coloured compounds
Dcatalytic abilities
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Question 55
waec2009
Which of the following elements has the electronic configuration:1s22s22p63s23p1? [11Na, 13A1, 14N,16S]
AAl
BNa
CN
DS
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Question 56
waec2009
How many orbitals are associated with the p-sub energy level?
A2
B3
C5
D6
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Question 57
waec2009
Consider the reaction represented by the equation: 23892U + 10 → 13956Ba + 9436Kr + 310n. The reaction represents a
Anuclear fission
Bnuclear fusion
Cradioactive decay
Dspontaneous disintegration
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Question 58
waec2009
If 100 atoms of element X contains 70 atoms of 9X and 30 atoms of 11X, calculate the relative atomic mass of X
A9.6
B10.6
C11.6
D20.0
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Question 59
waec2009
How many protons does 4020Ca contain?
A20
B30
C40
D60
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Question 60
waec2009
Which of the following scientists discovered the neutron?
