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What mass of silver is deposited when a current of 2.6 A is passed through a solution of a silver salt for 40 minutes? [Ag= 108 ; F=96500C]
A6.89g
B6.93g
C6.98g
D7.04g
E7.12g
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Question 12
neco2003
Naturally occurring lithium consists of 90% \( ^7_3Li \text{ and 10% } ^6_3 Li. \) What is the relative atomic mass of lithium?
A6
B6.8
C6.9
D7
E7.1
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Question 13
neco2003
Why does the treatment of cotton fabrics with dilute acids weaken the materials?
ACotton is hydrolysed completely to glucose
BThe fabrics are soluble in dilute acids
CThe molecular chains are partially broken
DThe molecular chain length f the fabric increases
EThe thread holding the fabric together Is completely destroyed.
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Question 14
neco2003
An organic compound gave the following results on analysis: C = 29.3% ; H = 5.7%; Br = 65%.
What is the empirical formula of the compound? [C = 12, H = 1, Br=80]
ACH3Br
BC2H5Br
CC3H5Br
DC3H7Br
EC4H9Br
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Question 15
neco2003
What mass of copper is deposited when 6.5g of granulated zinc reacts with excess copper(II) tetraoxosulphate(VI) solution?
The equation for the reaction is: Zn(s) + \( CuSO_4(aq)→ ZnSO_4(aq)+ Cu(s)\)[CU= 64; Zn=65]
A3.2 g
B3.25 g
C6.4 g
D6.5 g
E64.0 g
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Question 16
neco2003
Which element is the most electronegative?
Acalcium
Bfluorine
Ciodine
Doxygen
Esodium
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Question 17
neco2003
What change will occur to the equilibrium mixture
\( 2CrO^{2-}_4(aq) + 2H^+(aq) ⇔ Cr_2O^{2-}_7(aq) + H_2O(l) \) when excess sodium hydrogen solution is added?
AA yellow precipitate of Cr(OH)3 is formed
BAn orange precipitate of Cr(OH)3 is formed
CThe colour changes from orange to yellow
DThe colour changes from yellow to orange
EThere is no visible reaction.
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Question 18
neco2003
What is the IUPAC name of CH3CCI=C(CH3)2?
A2-chloro -3 methylbut -2yne
B2 -chloro -3 methylbut -2ene
C2 -chloro -3 methylbutene
D3- methyl -2-chlorobut -2-ene
E3- methyl -2. chlorobut -2 yne
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Question 19
neco2003
Which formula is used to indicate the degree of acidity of an acid?
A\( [H^+] = ^{\text{mass of acid relative}} molecular mass of acid \)
BF = number of H+ = ions x molar mass of the acid
CKw = [H+][OH-]
DpH = - log10[H+]
EpKa = -log10Ka
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Question 20
neco2003
Which compound will give propane when it Is dehy drated by an excess of hot, concentrated tetraoxosvlphate(VI) acid?
ACH3CH2CHO
BCH3CH2CH2OH
CCH3CH2COQH
DCH3CH20CH
ECH3CH3OH
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Question 21
neco2003
A calcium atom and a calcium ion have the same
Achemical properties
Belectric charge
Celectronic structure
Dnumber of electrons
Enumber of neutrons
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Question 22
neco2003
Which is NOT a synthetic polymer?
Anylon
BOrion
CPerspex
Dpolystyrene
Ewool
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Question 23
neco2003
The reaction C2H6 → C2H + H2 is known as
Adehydration
Bdehydrogenation
Cdisplacement
Dhydrogenation
Ereduction
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Question 24
neco2003
The boiling point of water is higher than the boiling point of ethanol because
Athe bonding in water is electrovalent (ionic) whereas the bonding in ethanol is convalent
Bthe hydrogen bonding between water molecules is stronger than the hydrogen bonding between ethanol molecules
Cwater has a higher lattice energy than ethanol.
Dwater has hydrogen bonding between its molecules but ethanol has no hydrogen bonging between its molecules;
Ewater is a better solvent than ethanol.
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Question 25
neco2003
B is an isotope of the element \(^{238} _{92}Ur\). The isotope B has
A46 protons and 119 neutrons
B92 protons and 92 neutrons
C92 protons and 146 neutrons
D92 protons and 238 neutrons
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Question 26
neco2003
The number of hydrogen ions in 1.0dm\(^3\) of a 0.25 mole tetraoxosulphate(Vl) acid solution is
[Avogadro c x 10\(^{23}\)]
A1.45x1023
B1.50 x l023
C3.00x1023
D3.15x1023
E6.00x1023
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Question 27
neco2003
Chlorine is used in water purification because it
Ableaches impurities in the water
Bdecolorizes water
Cdestroys bacteria
Dis extremely soluble in water
Eis pleasant tasting
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Question 28
neco2003
Which statement is NOT true about the composition of starch?
AIt contains only the atoms of carbon, hydrogen oxygen
BIt is a polysaccharide
CIts empirical formula is C2H20.
DIt is made from the monomerC6H12O6.
EThe hydrogen and oxygen atoms are in the ratio 2:1.
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Question 29
waec2003
Which of the following processes will pollute water?
AExposure of a body of water ultraviolet rays
BDischarge of industrial effluents effluents into water ways
CPassage of river water through a send bed
DAddition of a measured quantity of chlorine to water
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Question 30
waec2003
What are the two gases associated with the formation of acid rain?
