NECO 2018 ACCURATE ANSWER FOR CHEMISTRY OBJ AND ESSAY COMPLETE📝📝✅✅

☎☎☎CONTACT US 📞or WHATSAPP 08100173622 ☎☎☎*

*CHEMISTRTY – Obj*

*1DDDBCADBBC*

*11DCDBDDCEDC*

*21BBDEAAACCA*

*31BCCBDACDCB*

*41EAEBEECBAC*

*51DADCCAABEB*
=======================================
*CHEMISTRY- Theory*

1a)
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’
1bi)
CLICK HERE FOR THE 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 .
2KMnO 4 ( aq) +16 HCl– — > 2MaCl 2( aq) + 8H2O
( s ) +5Cl 2( 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
1ci )
GIVEN
P 1=( 745 -13 .5) mmHg =731 .5mmHg
T 1=( 16+ 273) k = 289k
P 2=S .P =760 mmHg
T 2=S .T =273 k
V 1=40cm ^3
using the general gas equation
P 1V 1/T 1=P 2V 2/T 2
V 2=731 .5* 40* 273/760 * 289
V 2=36. 4cm^3
the volume of the gas at S. T .P is 36.4 cm^3
1cii )
i ) Nature of reactions
ii ) presence of a catalyst
================================

6ai)
NH 4^+( aq) + OH^-( aq ) +HCl( aq) – – -> NH 4Cl
( aq) +H 2O ( i )
6aii )
the student got the choice of indicator wrong
6aiii )
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
6ci )
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 )
6di)
GIVEN:
mass of P = 9g
molar mass of P =80 g/mol
: Number of mole of P presnt =mass/molar mass
=9/80 =0.1125 moles
solubility =0 .1125 /60* 100= 1.875 mol/dm ^3
6dii )
C 2H 5OH( aq ) +H 2SO4 ( aq) – — ->
C 2H 5HSO 4( aq ) +H2O ( i )
C 2H 5HSO 4( aq ) — — > C 2H4( aq ) +H2 SO4( 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 .
=======================================

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
3aii )
i ) solubility
ii ) boiling points
iii ) densities
3aiii )

3bi)
catalyst are substance which alter the rate of a
chemical reaction but not themselves used up in
the process .
3bii )
i ) they are proteinous in nature
ii ) they alter the rate of a chemical reaction
iii ) they are not use themselves up in the
reaction
3ci )
The solution turn from blue to white as a
magnesium displace copper from its salt
3cii )
Mg ( aq) +CuSO 4( aq) – – — -> MgSO 4 ( aq) + Cu( s )
3di)
Equation Reaction:
2Na ( s ) +O 2 ( q) — – — > Na 2O 2( s )
Number of moles of soduim = mass/molar mass
=5. 95/23= 0.2587 moles
reactive ratio of sodium to its oxide is 2: 1
therefore number of moles of
Na2 O 2=0 .2587 /2=0. 129moles
mass of oxide
=0. 129* [( 23 *2) + ( 16* 2)]
=0. 129* 78
=10g
3dii )
i ) dissolving an acid on hydride in water
ii ) combination of constituent element
3diii )
washing soda ( NaCO3. 10 H2O )
=======================================

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
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
4aiii )
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
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
II . C is ethanol [ C 2H 5OH] , D is ethylethanoate
[CH3 COOC2 H5]
III . Functional group is -OH
IV . CH3COOH ( aq) ethanoic acid + C 2H 5OH( aq) c
— – — > conc H2SO 4( catalyst ) – – — ->
CH3COOC 2H 5( i ) + H 2O ( i )
4ci )
CH
( CH3) 3, CH3 CH2CH2CH 3, CH3CH2CH 2CH2OH/
Increasing boiling points
4cii )
i ) Bubbles formed at the bottom of liquid rise to
the surface
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
4civ )
I. N2 O 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

*☎☎☎CONTACT US 📞or WHATSAPP 08100173622 ☎☎☎*

*CHEMISTRTY – Obj*

*1DDDBCADBBC*

*11DCDBDDCEDC*

*21BBDEAAACCA*

*31BCCBDACDCB*

*41EAEBEECBAC*

*51DADCCAABEB*
=======================================
*CHEMISTRY- Theory*

1a)
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’
1bi)
CLICK HERE FOR THE 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 .
2KMnO 4 ( aq) +16 HCl– — > 2MaCl 2( aq) + 8H2O
( s ) +5Cl 2( 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
1ci )
GIVEN
P 1=( 745 -13 .5) mmHg =731 .5mmHg
T 1=( 16+ 273) k = 289k
P 2=S .P =760 mmHg
T 2=S .T =273 k
V 1=40cm ^3
using the general gas equation
P 1V 1/T 1=P 2V 2/T 2
V 2=731 .5* 40* 273/760 * 289
V 2=36. 4cm^3
the volume of the gas at S. T .P is 36.4 cm^3
1cii )
i ) Nature of reactions
ii ) presence of a catalyst
================================

6ai)
NH 4^+( aq) + OH^-( aq ) +HCl( aq) – – -> NH 4Cl
( aq) +H 2O ( i )
6aii )
the student got the choice of indicator wrong
6aiii )
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
6ci )
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 )
6di)
GIVEN:
mass of P = 9g
molar mass of P =80 g/mol
: Number of mole of P presnt =mass/molar mass
=9/80 =0.1125 moles
solubility =0 .1125 /60* 100= 1.875 mol/dm ^3
6dii )
C 2H 5OH( aq ) +H 2SO4 ( aq) – — ->
C 2H 5HSO 4( aq ) +H2O ( i )
C 2H 5HSO 4( aq ) — — > C 2H4( aq ) +H2 SO4( 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 .
=======================================

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
3aii )
i ) solubility
ii ) boiling points
iii ) densities
3aiii )
CLICK HERE FOR THE DIAGRAM
3bi)
catalyst are substance which alter the rate of a
chemical reaction but not themselves used up in
the process .
3bii )
i ) they are proteinous in nature
ii ) they alter the rate of a chemical reaction
iii ) they are not use themselves up in the
reaction
3ci )
The solution turn from blue to white as a
magnesium displace copper from its salt
3cii )
Mg ( aq) +CuSO 4( aq) – – — -> MgSO 4 ( aq) + Cu( s )
3di)
Equation Reaction:
2Na ( s ) +O 2 ( q) — – — > Na 2O 2( s )
Number of moles of soduim = mass/molar mass
=5. 95/23= 0.2587 moles
reactive ratio of sodium to its oxide is 2: 1
therefore number of moles of
Na2 O 2=0 .2587 /2=0. 129moles
mass of oxide
=0. 129* [( 23 *2) + ( 16* 2)]
=0. 129* 78
=10g
3dii )
i ) dissolving an acid on hydride in water
ii ) combination of constituent element
3diii )
washing soda ( NaCO3. 10 H2O )
=======================================

*☎☎☎CONTACT US 📞or WHATSAPP 08100173622 ☎☎☎*

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
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
4aiii )
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
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
II . C is ethanol [ C 2H 5OH] , D is ethylethanoate
[CH3 COOC2 H5]
III . Functional group is -OH
IV . CH3COOH ( aq) ethanoic acid + C 2H 5OH( aq) c
— – — > conc H2SO 4( catalyst ) – – — ->
CH3COOC 2H 5( i ) + H 2O ( i )
4ci )
CH
( CH3) 3, CH3 CH2CH2CH 3, CH3CH2CH 2CH2OH/
Increasing boiling points
4cii )
i ) Bubbles formed at the bottom of liquid rise to
the surface
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
4civ )
I. N2 O 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

*☎☎☎CONTACT US 📞or WHATSAPP 08100173622

☎☎☎*

 

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