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E2023 & E2022 CHEMISTRY 3 hours
&II
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NATIONAL EXAMINATIONS COUNCIL
Senior School Certificate Examination
3 hours
CHEMISTRY III & II
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CHEMISTRY OBJ:
1-10: DADBCADBCA
11-20: DCDBDBEDDC
21-30: CBDEDBAAEA
31-40: ECCADAEDEB
41-50: EAADDACBBC
51-60: ADDDBACBEB
11-20: DCDBDBEDDC
21-30: CBDEDBAAEA
31-40: ECCADAEDEB
41-50: EAADDACBBC
51-60: ADDDBACBEB
(1a)
I. Isotopy is a phenomenon whereby an atom of an element excite different mass number but have the same atomic number.
I. Isotopy is a phenomenon whereby an atom of an element excite different mass number but have the same atomic number.
II. Isomerism is existent of two or more compound (known as isomers) with the same molecular formulae but different molecular structure
(1aii)
(i) Deuterium
(ii) Tritium
(i) Deuterium
(ii) Tritium
(1bi)
DIAGRAM
DIAGRAM
Bottomed flask and set up the apparatus as shown. Add conc HCl gradual into the flask through the thistle funnel pass the gas produced through water and concentrated tetraoxosulphate (iv) and collect it by downward delivery.
2KMnO4(aq)+16HCl---->2MaCl2(aq)+8H2O(s)+5Cl2(aq)
2KMnO4(aq)+16HCl---->2MaCl2(aq)+8H2O(s)+5Cl2(aq)
(1bii)
(i) It is use as a bleaching agent
(ii) It is use as disinfectant in the treatment of water
(iii)it is use as an oxidizing agent
(i) It is use as a bleaching agent
(ii) It is use as disinfectant in the treatment of water
(iii)it is use as an oxidizing agent
(1ci)
GIVEN
P1=(745-13.5)mmHg =731.5mmHg
T1=(16+273)k=289k
P2=S.P=760mmHg
T2=S.T=273k
V1=40cm^3
using the general gas equation
P1V1/T1=P2V2/T2
V2=731.5*40*273/760*289
V2=36.4cm^3
The volume of the gas at S.T.P is 36.4cm^3
(1cii)
(i) Nature of reactions
(ii) Presence of a catalyst
(i) Nature of reactions
(ii) Presence of a catalyst
===============================================
(3ai)
A homologous series is a family of organic compound which follows a regular structural pattern in which each successive member differ in its molecular formula. By-CH2-GROUP
A homologous series is a family of organic compound which follows a regular structural pattern in which each successive member differ in its molecular formula. By-CH2-GROUP
(3aii)
(i) Solubility
(ii) Boiling points
(iii) Densities
(i) Solubility
(ii) Boiling points
(iii) Densities
(3aiii)
DIAGRAM
DIAGRAM
(3bi)
A catalyst is a substance which alter the rate of a chemical reaction without itself being used up in the process.
A catalyst is a substance which alter the rate of a chemical reaction without itself being used up in the process.
(3bii)
(i) They are proteinous in nature
(ii) They alter the rate of a chemical reaction
(iii) They remain unchanged in the reaction
(3ci)
The solution turn from blue to white as a magnesium displace copper from its salt
(3cii)
Mg(aq)+CuSO4(aq)-----> MgSO4(aq)+ Cu(s)
(3di)
Equation Reaction:
2Na(s)+O2(q)----->Na2O2(s)
Number of moles of soduim =mass/molar mass =5.95/23=0.2587moles
Reactive ratio of sodium to its oxide is 2:1
Therefore number of moles of Na2O2=0.2587/2=0.129moles
Mass of oxide
=0.129*[(23*2)+(16*2)]
=0.129*78
=10g
2Na(s)+O2(q)----->Na2O2(s)
Number of moles of soduim =mass/molar mass =5.95/23=0.2587moles
Reactive ratio of sodium to its oxide is 2:1
Therefore number of moles of Na2O2=0.2587/2=0.129moles
Mass of oxide
=0.129*[(23*2)+(16*2)]
=0.129*78
=10g
(3dii)
(i) Dissolving an acid anhydride in water
(ii) Combination of constituent element
(i) Dissolving an acid anhydride in water
(ii) Combination of constituent element
(3diii)
Washing soda (NaCO3. 10H2O)
Washing soda (NaCO3. 10H2O)
===============================================
(4ai)
From the collision theory the rate of chemical reactions depend on the frequency of effective collisions cones that the result in reaction between reactant particles
From the collision theory the rate of chemical reactions depend on the frequency of effective collisions cones that the result in reaction between reactant particles
(4aii)
Cracking means breaking down or decomposition of a compound by the action of heat alone while Reforming is the breaking down of a compound by the use of a catalyst
Cracking means breaking down or decomposition of a compound by the action of heat alone while Reforming is the breaking down of a compound by the use of a catalyst
(4aiii)
They are the most important processes for the commercial production of gasoline and diesel fuel
They are the most important processes for the commercial production of gasoline and diesel fuel
(4bi)
I. Limestone: The limestone decomposes when heated to yield carbon(iv)oxide which is a major reactant
I. Limestone: The limestone decomposes when heated to yield carbon(iv)oxide which is a major reactant
II. Ammonia: The ammonia reacts with the carbon(iv)oxide ammonium hydrogen trioxocarbonate(iv)
(4bii)
I. B belong to the class of compound called carbohydrates
I. B belong to the class of compound called carbohydrates
II. C is ethanol [C2H5OH] , D is ethylethanoate [CH3COOC2H5]
III. Functional group is -OH
IV. CH3COOH(aq)ethanoic acid + C2H5OH(aq)c ----->conc H2SO4(catalyst) -----> CH3COOC2H5(i) + H2O(i)
(4ci)
CH(CH3)3,CH3CH2CH2CH3,CH3CH2CH2CH2OH
------------------------->
Increasing boiling points
CH(CH3)3,CH3CH2CH2CH3,CH3CH2CH2CH2OH
------------------------->
Increasing boiling points
(4cii)
(i) Bubbles formed at the bottom of liquid rise to the surface
(ii) Temperature remain steady
(ii) Temperature remain steady
(4ciii)
I. Addition of sodium chloride crystals raises the boiling point of water
II. Reduction in atmospheric pressure lowers the boiling point of water
I. Addition of sodium chloride crystals raises the boiling point of water
II. Reduction in atmospheric pressure lowers the boiling point of water
(4civ)
I. N2O has oxidation state of +1 for Nitrogen
II. NO has oxidation state of +2 for Nitrogen
III. NO2 has Oxidation state of +4 For Nitrogen
II. NO has oxidation state of +2 for Nitrogen
III. NO2 has Oxidation state of +4 For Nitrogen
6ai)
NH4^+(aq)+OH^-(aq)+HCl(aq)---> NH4Cl(aq)+H2O(i)
NH4^+(aq)+OH^-(aq)+HCl(aq)---> NH4Cl(aq)+H2O(i)
6aii)
the student got the choice of indicator wrong
the student got the choice of indicator wrong
6aiii)
phenolphthalein is used when a strong base is present. aqueaous ammonia is a weak base
phenolphthalein is used when a strong base is present. aqueaous ammonia is a weak base
6b)
i)gluclose and fructose
ii)invertase
iii)delivery tube
iv)glucose
i)gluclose and fructose
ii)invertase
iii)delivery tube
iv)glucose
6ci)
white phosphorus and red phosphorus
white phosphorus and red phosphorus
6cii)
I. has no effect of red litmus paper
II. changes damp blue litmus paper pink
III. Reacts directly with alkali to yield a trioxocarbonate(iv)
I. has no effect of red litmus paper
II. changes damp blue litmus paper pink
III. Reacts directly with alkali to yield a trioxocarbonate(iv)
6di)
GIVEN:
mass of P= 9g
molar mass of P =80g/mol
: Number of mole of P presnt =mass/molar mass
=9/80=0.1125moles
solubility =0.1125/60*100=1.875mol/dm^3
GIVEN:
mass of P= 9g
molar mass of P =80g/mol
: Number of mole of P presnt =mass/molar mass
=9/80=0.1125moles
solubility =0.1125/60*100=1.875mol/dm^3
6dii)
C2H5OH(aq) +H2SO4(aq)----> C2H5HSO4(aq)+H2O(i)
C2H5HSO4(aq)---->C2H4(aq)+H2SO4(aq) ethene
C2H5OH(aq) +H2SO4(aq)----> C2H5HSO4(aq)+H2O(i)
C2H5HSO4(aq)---->C2H4(aq)+H2SO4(aq) ethene
6diii)
Bromine Exists as liquid at room temperature because there is decrease in votality down the group of the halogens due to increasing strength of the van der waal's force.
Bromine Exists as liquid at room temperature because there is decrease in votality down the group of the halogens due to increasing strength of the van der waal's force.
=============================