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#Post#: 299--------------------------------------------------
FREE 100% CORRECT WAEC GCE CHEMISTRY ANSWERS AVAILABLE HERE
By: Ebenezer Date: September 23, 2013, 9:20 am
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[color=lime]We just dont love it when our members perform badly
in their exam thats why we've decided to post it[/font]
Chemistry Theory Answers
(1ai) Mass number is the sum of proton and reaction of an
element while Atomic number is the number of protons in an
element.
(1aii)
(I) Mass No= proton No + Neutron
34 = proton No + 18
Proton No= 34-18=16
Number of electrons =16
(II) 2,8,6
(1aiii) The relative atomic mass of chloride is not whole number
because its exihibit isotopy
(1bi) Transition elements are elements that occupy between
period 2 and 3 of the periodic table and have partially filled
d-orbitals
(1bii) Copprer , Iron
(1biii)
(I) Because they have partially filled 3d orbitals
(II) Because of the presence of ligands
(1ci) Ionic radius, Electronegativity,electron affinity
(1cii)
(i) Because the distance between the nucleus and neigbouring
shell is shorter when compared with Na+
(ii) Because Trioxocarbonate of Na are insoluble in nature.
#Post#: 300--------------------------------------------------
Re: FREE 100% CORRECT WAEC GCE CHEMISTRY ANSWERS AVAILABLE HERE
By: Ebenezer Date: September 23, 2013, 9:50 am
---------------------------------------------------------
We just dont love it when our members perform badly in their
exam thats why we've decided to post it
Chemistry Theory Answers
(1ai) Mass number is the sum of proton and reaction of an
element while Atomic number is the number of protons in an
element.
(1aii)
(I) Mass No= proton No + Neutron
34 = proton No + 18
Proton No= 34-18=16
Number of electrons =16
(II) 2,8,6
(1aiii) The relative atomic mass of chloride is not whole number
because its exihibit isotopy
(1bi) Transition elements are elements that occupy between
period 2 and 3 of the periodic table and have partially filled
d-orbitals
(1bii) Copprer , Iron
(1biii)
(I) Because they have partially filled 3d orbitals
(II) Because of the presence of ligands
(1ci) Ionic radius, Electronegativity,electron affinity
(1cii)
(i) Because the distance between the nucleus and neigbouring
shell is shorter when compared with Na+
(ii) Because Trioxocarbonate of Na are insoluble in nature.
(2ai) Graham's law of diffusion states that the rate of
diffusion of gas at constant temperature and pressure
is inversely proportional to the square root of its
vapour density.
(2aii)
(I)
PB = 1.013*10^5Nm^-3
VB = 5dm^3
Pc= 3.039* 10^5Nm^-2
Vc= 5dm^3
PT= PB+PC
PT = 1.013*10^5+3.03*10^5
PT= 4.052*10^5Nm^-2
(II)
PT=(1.013*10^5*10) + (3.03*10^5*10)
PT= 4.052*10^6Nm^-2
(2bi)
No of mole of methane = 0.50mol,
No of mole of oxygen= 1.5mol,
1mol of methane produces 2 mol of oxygen,
0.50mol of methane produces 2/1 * (0.50) = 1.0 mol
of oxygen
Methane is in excess of oxygen
(2bii)
2mol of oxygen produces 2moles of steam,
1.5mol of oxygen produces 2/2*(1.5) = 1.5moles of
steam
(2biii)
3.0 = no of molecules/ 6.02*10^23
no of molecules = 3.0*6.02*10^23 = 18.06 * 10^23
particles
=1.806*10^24
(2c) To 1cm^3 of unknown substance, add calcium
hydroxide. The presence if milky solution confirms the
presence of carbon(iv)oxide
(2di)
(I) By using calcium Chloride
(II) Dry agent
(2dii) Because it is less denser than air
(2diii) Hydrogen perioxide and Cu are formed
#Post#: 301--------------------------------------------------
Re: FREE 100% CORRECT WAEC GCE CHEMISTRY ANSWERS AVAILABLE HERE
By: Ebenezer Date: September 23, 2013, 10:10 am
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(4ai)
C2H6+7/2 O2 -> 2CO2 + 3H2O
2C2H6+7 O2 -> 4CO2+6H2O
C2H4+3O2->2CO2+2H2O
C2H2+5/2 O2 -> 2CO2+H2O
2C2H2+5O2-> 4CO2+2H2O
(4aii)
- C2H6 contributes to green house effect because it is
produced by decomposition of matter.
- C2H4 contributes to green house effect because it is
unsaturated and produce smoky flame.
- C2H2 also produce smoky flame
(4aiii) C2H6 is economical because it is saturated
(4b)
(i) Ethanoic acid
(ii) Chloroethane
(iii) Propylhydrogentetraoxosulphate(iv)
(4c)
i. Hydrolysis is the addition of water molecules to a
substance
ii. Hydration is the removal of water molecules from a
substance
iii. Functional group is an ions, atoms, or a group of
atoms or radicals that determine the chemical
properties of a substance
(4d)
CH3CH2CH3 < CH3CH2CH2CH2OH < CH3CH2OH
This is because alkanols naturally are soluble in water
and their solubility decreases as the number of carbon
atom increases
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