CHEMISTRY-OBJ!
1CEDEABCCEC
11ACDCBCDCAB
21EAECBCDBAC
31BBBACCBBDD
41ACDEEACBDB
51CCEBCBBCBD
=====================================
(4ai)
Sublimation is the process whereby a solid changes state directly to the gaseous state without passing through the liquid state upon heating
(4aii)
Iodine and Ammonium chloride
(4b)
(i) He may have conducted the experiment in a partial vacuum
(ii) Addition of impurities like salt
(iii) T°K = 78 +273 = 351K
(4ci)
(i)presence of moisture
(ii)presence of oxygen
(4cii)
4Al(NO3)3(s) ------> 2Al2O3(s) +3O2(q) + 12NO2(q)
(4ciii)
(i)sols and gels
(ii)Aerosols
(iii)Emulsion
(4d)
Using CAVA/CBVB =nA/nB
0.122*20.50/CB * 25.00 = 2/1
CB = 0.05002moles/dm^3
Using :
Gram conc = molar conc * molar mass
Molar mass of hydrated salt = 6.203 * 1/0.05002
=124g/mol
Now;
106 + (18x)= 124
18x = 124 - 106
18x = 18
x = 18/18 = 1
SaH was NaCO3. H2O
(4e)
(i)the metal is potassium
(ii) period 4
(iii)group 1
(iv)2k(s) + 2H2O ----> 2NaOH(aq) + H2(q)
=====================================
(3ai)
Chemical industry are companies that produce industrial chemicals
(3aii)
- Favourable climatic conditions
- It's nearness to the source of raw materials
- The availability of space to store raw materials
(3b)
(i) It is aldose and it contains alkanal (-CHO) group
(ii) Brick red precipitate is formed
(iii) Reducing sugar possess a free aldehyde (-CHO) or ketone (-C=O) group while non reducing sugar a free aldehyde or ketone group is lacking
(3ci)
(i) Pollution is the release of unwanted materials into the environment which cause adverse change
(ii) Pollutant is a substance or energy introduced into the environment that has undesired effects or adversely effects the usefulness of a resource
(3cii)
(i)Plastic
(ii)Polythene
(iii)Pesticides
(3ciii)
VC2H2=?
MCaCa=3.2g
MCaCa=40+(2*12)
=40+24
=64glmol
n=m/m=3.2/64
n=0.05mole of CaC2
CaC2+2H2O ---> Can(OH)2+C2H2
0.05mole of CaC2 ----> 0.05mole of C2H2 because the mole ratio are equal
NC2H2=0.05moles
n=V/VM
VC2H2=n*Vm = 0.05*22.4
VC2H2=1.12dm³
(3d)
(i)Na2CO3 ----> soluble
(ii)K2CO3 ----> soluble
(iii)ZnCO3 ----> insoluble
(iv)(NH4)2CO3 ----> soluble
=====================================
(2aii)
Avogadro's law states that equal volumes of all gases under the same temperature and pressure contain the same number of molecules
(2aii)
no2=?
2SO2(g) + O2 ---> 2SO3(g)
2 : 1 : 2
VSO2 = 7.50dm^3
nSO2 = V/Vm = 7.50/22.4 = 0.3348moles
2moles of SO2 ----> 1 moles of O2
0.3348 ----> x
x = 0.3348/2 = 0.1674moles
nO2 = 0.1674moles
np = n × L = 0.167 × 6.02 × 10^23
np = 1.008 × 10^23molecules
np = 1.01×10^23 molecules
(2bi)
(I) NaCl -----> Valency of chlorine is 1
(II) NaO2 -----> Valency of oxygen is 2
(III) Na3N ------> Valency of Nitrogen is 3
(2bii)
(i)Formation of black soap
(ii)Formation of glycerol
(iii)It helps in the precipitation of large biomolecules such as protein
(2ci)
(i)Na2O
(ii)MgO
(iii)CaO
(2cii)
Because they react with water to form acids
(2ciii)
- Reaction with sulphur
S(s) + O2(g) ---> SO2(g)
- Reaction with metals
4Na(s) + O2(g) ----> 2NaO(s)
(2di)
Ion is any atom or group of atoms which possess an electric charge
(2dii)
TABULATE PLS
ION : H^+, F^-, N^3+
NUMBER OF PROTONS: 1,9,13
NUMBER OF NEUTRONS : 0, 10, 14
NUMBER OF ELECTRONS : 0, 10, 10
(2ei)
Monosaccharide are simple six carbon sugar having the formula C6H12O6 eg glucose and it's isomers are fructose and galactose, both obtainable from fruits and honey
(2eii)
(i)fructose
(ii)galactose
=====================================
(1a)
Ammonium chloride ---> sublimation
Ink ---> chromatography
Iron filling ---> magnetic separation
(1aii)
-Example Of physical Change
(i)change of matter
(ii)evaporation of sodium chloride
-Example of chemical change
(i)burning of firewood
(ii)rusting of iron
(1bi)
(i)they are good reducing agent
(ii)they form basic oxide
(iii)they formed electro valent bonding
(1bii)
Aluminum tetraoxosulphate(vi) is prepared by the action of hot concentrated tetraoxosulphate(vi)acid on aluminum oxide
Al2O3(s) + 3H2SO4(aq)---->Al2(SO4)3(aq)+3H2O(i)
Aluminum tetraoxosulphate(vi) is moderately soluble in water
(1ci)
Hydrogen
(1cii)
(i)it is denser than air
(ii)it is very poisonous
(1ciii)
Pb(NO3)2+H2S---->Pbs+2HNO3
(1civ)
It turn black due to the formation of black lead (II) sulphide
(1di)
Water gas contains flammable gases whereas the producer gas contains both flammable and non-flammable gases
(1dii)
(I) Diamond ---> Octahedral in shape
(II) Graphite ---> Hexagonal in shape
(1e)
(i) For manufacturing of ammonia and fertilizer
(ii) It is used as a refrigerant and also used to shrink metal parts
(iii) It is used in grinding substances that are too tough to grind at normal temperature
=====================================
COMPLETED!..
2019 NECO CHemistry Objective and essay Questions and Answers is available at 9Jatechs, get verified CHemistry Objective and essay neco questions and answers midnight before the commencement of the examination.
Note:9Jatechs 2019 NECO CHemistry Objective and essay Questions and Answers is N600 MTN Card
Note: please do not call our number, simply send message on whatsapp or using SMS
For More Info Whatsapp 08065889844 or click the whatsapp icon on the left side of our platform to chat with us.
2019/2020 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for 2019 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for CHemistry Objective and essay.
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
All updates concerning Neco is been posted at Neco exam forum and all updates concerning Waec is posted at Waec Exams forum forum.
1CEDEABCCEC
11ACDCBCDCAB
21EAECBCDBAC
31BBBACCBBDD
41ACDEEACBDB
51CCEBCBBCBD
=====================================
(4ai)
Sublimation is the process whereby a solid changes state directly to the gaseous state without passing through the liquid state upon heating
(4aii)
Iodine and Ammonium chloride
(4b)
(i) He may have conducted the experiment in a partial vacuum
(ii) Addition of impurities like salt
(iii) T°K = 78 +273 = 351K
(4ci)
(i)presence of moisture
(ii)presence of oxygen
(4cii)
4Al(NO3)3(s) ------> 2Al2O3(s) +3O2(q) + 12NO2(q)
(4ciii)
(i)sols and gels
(ii)Aerosols
(iii)Emulsion
(4d)
Using CAVA/CBVB =nA/nB
0.122*20.50/CB * 25.00 = 2/1
CB = 0.05002moles/dm^3
Using :
Gram conc = molar conc * molar mass
Molar mass of hydrated salt = 6.203 * 1/0.05002
=124g/mol
Now;
106 + (18x)= 124
18x = 124 - 106
18x = 18
x = 18/18 = 1
SaH was NaCO3. H2O
(4e)
(i)the metal is potassium
(ii) period 4
(iii)group 1
(iv)2k(s) + 2H2O ----> 2NaOH(aq) + H2(q)
=====================================
(3ai)
Chemical industry are companies that produce industrial chemicals
(3aii)
- Favourable climatic conditions
- It's nearness to the source of raw materials
- The availability of space to store raw materials
(3b)
(i) It is aldose and it contains alkanal (-CHO) group
(ii) Brick red precipitate is formed
(iii) Reducing sugar possess a free aldehyde (-CHO) or ketone (-C=O) group while non reducing sugar a free aldehyde or ketone group is lacking
(3ci)
(i) Pollution is the release of unwanted materials into the environment which cause adverse change
(ii) Pollutant is a substance or energy introduced into the environment that has undesired effects or adversely effects the usefulness of a resource
(3cii)
(i)Plastic
(ii)Polythene
(iii)Pesticides
(3ciii)
VC2H2=?
MCaCa=3.2g
MCaCa=40+(2*12)
=40+24
=64glmol
n=m/m=3.2/64
n=0.05mole of CaC2
CaC2+2H2O ---> Can(OH)2+C2H2
0.05mole of CaC2 ----> 0.05mole of C2H2 because the mole ratio are equal
NC2H2=0.05moles
n=V/VM
VC2H2=n*Vm = 0.05*22.4
VC2H2=1.12dm³
(3d)
(i)Na2CO3 ----> soluble
(ii)K2CO3 ----> soluble
(iii)ZnCO3 ----> insoluble
(iv)(NH4)2CO3 ----> soluble
=====================================
(2aii)
Avogadro's law states that equal volumes of all gases under the same temperature and pressure contain the same number of molecules
(2aii)
no2=?
2SO2(g) + O2 ---> 2SO3(g)
2 : 1 : 2
VSO2 = 7.50dm^3
nSO2 = V/Vm = 7.50/22.4 = 0.3348moles
2moles of SO2 ----> 1 moles of O2
0.3348 ----> x
x = 0.3348/2 = 0.1674moles
nO2 = 0.1674moles
np = n × L = 0.167 × 6.02 × 10^23
np = 1.008 × 10^23molecules
np = 1.01×10^23 molecules
(2bi)
(I) NaCl -----> Valency of chlorine is 1
(II) NaO2 -----> Valency of oxygen is 2
(III) Na3N ------> Valency of Nitrogen is 3
(2bii)
(i)Formation of black soap
(ii)Formation of glycerol
(iii)It helps in the precipitation of large biomolecules such as protein
(2ci)
(i)Na2O
(ii)MgO
(iii)CaO
(2cii)
Because they react with water to form acids
(2ciii)
- Reaction with sulphur
S(s) + O2(g) ---> SO2(g)
- Reaction with metals
4Na(s) + O2(g) ----> 2NaO(s)
(2di)
Ion is any atom or group of atoms which possess an electric charge
(2dii)
TABULATE PLS
ION : H^+, F^-, N^3+
NUMBER OF PROTONS: 1,9,13
NUMBER OF NEUTRONS : 0, 10, 14
NUMBER OF ELECTRONS : 0, 10, 10
(2ei)
Monosaccharide are simple six carbon sugar having the formula C6H12O6 eg glucose and it's isomers are fructose and galactose, both obtainable from fruits and honey
(2eii)
(i)fructose
(ii)galactose
=====================================
(1a)
Ammonium chloride ---> sublimation
Ink ---> chromatography
Iron filling ---> magnetic separation
(1aii)
-Example Of physical Change
(i)change of matter
(ii)evaporation of sodium chloride
-Example of chemical change
(i)burning of firewood
(ii)rusting of iron
(1bi)
(i)they are good reducing agent
(ii)they form basic oxide
(iii)they formed electro valent bonding
(1bii)
Aluminum tetraoxosulphate(vi) is prepared by the action of hot concentrated tetraoxosulphate(vi)acid on aluminum oxide
Al2O3(s) + 3H2SO4(aq)---->Al2(SO4)3(aq)+3H2O(i)
Aluminum tetraoxosulphate(vi) is moderately soluble in water
(1ci)
Hydrogen
(1cii)
(i)it is denser than air
(ii)it is very poisonous
(1ciii)
Pb(NO3)2+H2S---->Pbs+2HNO3
(1civ)
It turn black due to the formation of black lead (II) sulphide
(1di)
Water gas contains flammable gases whereas the producer gas contains both flammable and non-flammable gases
(1dii)
(I) Diamond ---> Octahedral in shape
(II) Graphite ---> Hexagonal in shape
(1e)
(i) For manufacturing of ammonia and fertilizer
(ii) It is used as a refrigerant and also used to shrink metal parts
(iii) It is used in grinding substances that are too tough to grind at normal temperature
=====================================
COMPLETED!..
2019 NECO CHemistry Objective and essay Questions and Answers is available at 9Jatechs, get verified CHemistry Objective and essay neco questions and answers midnight before the commencement of the examination.
OUR SUBSCRIBERS GET QUESTIONS AND ANSWERS MIDNIGHT BEFORE THE COMMENCEMENT OF THE EXAM.
Time and Date for CHemistry Objective and essay 2019 NECO Examination.
Tuesday 2nd July- Paper III & II: Objective & Essay – Chemistry — 2:30pm- 5:30pm
Recommended: See 2019 NECO Official Exam Timetable >> 9Jatechs
2019 Neco CHemistry Objective and essay Answers will be deliver to all 9Jatechs Subscribers at night before the exam day, you can also get free exam Expo on our portal(i. e we are going to post answers 1hour after the exam start) just like we did during the previous Physics Practical 2018 NECO Examination
Procedure on How To Subscribe for 2019/2020 NECO CHemistry Objective and essay Questions and Answers.
2019 Neco CHemistry Objective and essay Answers will be deliver to all 9Jatechs Subscribers at night before the exam day, you can also get free exam Expo on our portal(i. e we are going to post answers 1hour after the exam start) just like we did during the previous Physics Practical 2018 NECO Examination
Procedure on How To Subscribe for 2019/2020 NECO CHemistry Objective and essay Questions and Answers.
We only Run our exam runz on whatsapp (2019 Neco WhatsApp Exam runz Package) because it is the fastest means of sending messages and photos online.
Answers delivery via whatsapp for CHemistry Objective and essay Questions and Answers Cost N600 MTN recharge card.
Procedure on how to Subscribe On Whatsapp
Answers delivery via whatsapp for CHemistry Objective and essay Questions and Answers Cost N600 MTN recharge card.
Procedure on how to Subscribe On Whatsapp
To subscribe for CHemistry Objective and essay Questions and Answers on WhatsApp you can send your MTN pin via WhatsApp or SMS.
(e.g. MTN Recharge Pin, Subject , Whatsapp Number to 08065889844)
Note:9Jatechs 2019 NECO CHemistry Objective and essay Questions and Answers is N600 MTN Card
Note: please do not call our number, simply send message on whatsapp or using SMS
For More Info Whatsapp 08065889844 or click the whatsapp icon on the left side of our platform to chat with us.
2019/2020 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for 2019 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for CHemistry Objective and essay.
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
2019/2020 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for 2019 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for CHemistry Objective and essay.
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
2019/2020 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for 2019 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for CHemistry Objective and essay.
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
ALSO SEE: Physics Objective and Essay 2018 Neco Gce Questions and Answers
2019/2020 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for 2019 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for CHemistry Objective and essay.
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
2019/2020 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for 2019 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for CHemistry Objective and essay.
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
2019/2020 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for 2019 Neco CHemistry Objective and essay Questions and answers now available, To get all questions and answers for CHemistry Objective and essay.
9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs). 9Jatechs deliver it answers at midnight to her subscribe. Expo for 2019 Neco CHemistry Objective and essay Questions and answers is also available on our portal (9Jatechs).
All updates concerning Neco is been posted at Neco exam forum and all updates concerning Waec is posted at Waec Exams forum forum.