Past 2017 top best forum
Today's Date
Nigeria free 2018 Gallery
9ja NOTICE: You are currently viewing this website as a Guest and are restricted from viewing some vital information. For more permissions on Earlyface.com.ng? Like posting Comments, Topics and Uploading contents without Verification And Moderator's approval. Fast loading and quick accessibility. Registration is required. Please Login or Register now to gain full access. It is fast and free!!

CLICK HERE NOW TO BECOME EARLYFACE MEMBER...


Author Topic: NECO 2022 CHEMISTRY ANSWERS (ESSAY & OBJ)  (Read 187 times)

0 Members and 0 Guests are viewing this topic.

Offline MANDINHO

  • VIP MEMBER
  • Gifted Member
  • *
  • Posts: 451
  • Vote for me: +13/-4
  • Location: NAIJA
NECO 2022 CHEMISTRY ANSWERS (ESSAY & OBJ)
« on: July 24, 2022, 06:37:05 pm »
FOLLOW THE PROCEDURE BELOW TO ENJOY OUR NECO NIGHT SOLUTIONS
👇👇👇👇👇👇
 
====================

CHEMISTRY SUBSCRIPTION

(i)Only-Password & Link. ₦500 MTN CARD

(ii)WhatsApp Fast Delivery(Pay early & Get Early Answers) ₦800 MTN CARD

SEND MTN-CARD + PHONE NUMBER + SUBJECT TO 07048281409

Offline MANDINHO

  • VIP MEMBER
  • Gifted Member
  • *
  • Posts: 451
  • Vote for me: +13/-4
  • Location: NAIJA
Re: NECO 2022 CHEMISTRY ANSWERS (ESSAY & OBJ)
« Reply #1 on: July 25, 2022, 10:52:16 am »
CHEMISTRY OBJ
01-10: BAAAACAACC
11-20: BCDCAAEDCC
21-30: ABCBDDAACC
31-40: CCACBACCDE
41-50: DDDEDDBDAD
51-60: CBACCEDBBD

COMPLETED

Offline MANDINHO

  • VIP MEMBER
  • Gifted Member
  • *
  • Posts: 451
  • Vote for me: +13/-4
  • Location: NAIJA
Re: NECO 2022 CHEMISTRY ANSWERS (ESSAY & OBJ)
« Reply #2 on: July 25, 2022, 12:01:13 pm »

CHEMISTRY THEORY SOLUTIONS

(1ai)
(i) KAl(SO₄)₂. 12H₂O
(ii) Na₂SO₄

(1aii)
Number of moles of sodium reascted = reacting mass/molar mass
= 3.6/23
= 0.1565moles
Number of moles of oxygen reacted = (1/4) x Number of sodium
= 1/4 x (3.6/23)
= 0.03913
Reacting mass of oxygen = Number of moles x molar mass
= 0.03913 x (16x2)
= 1.252grams

(1bi)
Air in gaseous form is first passed through caustic soda to remove CO₂. It is compressed and cooled until ut becomes a liquid at -200C. It is then led to a fractionating column. On distillation, Nitrogen which has a lowet boiling point of -196C is evolced first leaving behind Oxygen in liquid form. Further heating converts the liquid to a gas at -183C.

(1bii)
(i) It is used for combustion
(ii) It is used for artificial respiration

(1biii)
This is because room temperature is warmer

(1biv)
(i) Methyl orange
(ii) Phenophthalein

(1ci)
An ion is an atom or molecule which has a net electric charge due to the loss or gain of one or more electrons.

(1cii)
HCl gas doesn't contain ions

(1cii)
(i) Noble gases: Neon, Helium
(ii) Halogens: Iodine, Fluorine
(iii) Alkaline earth metals: Calcium, Magnesium

(1civ)
Halogens attain stable octet configuration by accepting an electron from donors Group I elements.

(1di)
A sol is a colloid where solid particles are dispersed in liquid medium.

(1dii)
Jelly

(1diii)
(i) Acid-base titrations are used to determine the percentage purity of a substance
(ii) Acid-base titrations are important to determine the number of water molecules in a hydrate.

==============================
(2ai)
A molar solution of a compound contains one mole or the molar mass of the compound in one dm of the solution.

(2aii)
(i) Identification of gases
(ii) Identification of acidic and metallic radicals

(2aiii)
(i) Purification of bauxite
(ii) Electrolysis of alumina

(2bi)


(2bii)
This is because of the presence of copper which is a transition metal

(2bii)
(i) Methanamide is a liquid while the rest amides are crystalline solids
(ii) Melting points and boiling points of aides are much higher than expected.

(2ci)
(i) Heavy chemicals are produced in very large quantities in industries While fine chemicals are produced in small quantities for specific purposes
(ii) Heavy chemicals are in a crude state While fine chemicals are purified.

(2cii)
(i) Million's reagent
(ii) Feeling's solution

(2ciii)
Graham's law of diffusion states that at a constant temperature and pressure the rate of diffusion of a gas is inversely proportional to the square root of its density.

(2civ)
RO₂/RCH₄  = √(MCH₄/MO₂)
5/(200/t) = √[(12+4)/(16x2)]
5t/200 = √16/32
t/40 = 1/√2
t = 40/√2
t = (40/√2) (√2/√2)
t = 20√2 seconds
Time taken = 28.28 seconds.

==============================

(4ai)
A hydrocarbon is an organic compound composed only of two elements carbon and hydrogen.

(4aii)
(i) Alkenes
(ii) Alkynes

(4aiii)
They are unsaturated compounds

(4aiv)
(i) Decrease in pressure
(ii) Finely divided zinc
(iii) Removal of hydrogen gas

(4bi)
(i) Electrovalent compounds conduct electricity While covalent compounds do not.
(ii) Electrovalent compounds dissolve in polar solvents While covalent compounds dissolve in non-polar solvents.

(4bii)
(i) High melting and boiling points
(ii) Exist mainly as solids at room temperature

(4biii)
(i) Ammonia, NH₃
(ii) Hydrogen chloride gas, HCl

(4ci)
(i) Potassium hexacyanoferrate(II)
(ii) It is a complex salt

(4cii)
(i) Wrought iron
(ii) Cast iron

(4ciii)
2H₂ + O₂ ---> 2H₂O
2     :   1   :    2
Reacting volumes;
40cm :  20cm  : 40cm
Residual volumes;
(50 - 40) (20 - 20)
= 10cm  = 0cm  = 40cm
Total residual volume = 10 + 40
= 50cm

==============================

(5ai)
(i)Chlorofluorocarbons
(ii) Hydrofluorocarbon

(5aii)
I - C₂H₂OH + H₂SO₄ --->C₂H₅HSO₄ + H₂O
II - C₂H₅HSO₄ ---> C₂H₄ +H₂SO₄

(5aiii)
(i) They incompletely filled d-orbitals
(ii) They exhibit variable oxidation state

(5bi)
(i) It is used in making aeroplane parts due to its tensile strength
(ii) It is used in making window frames because it cannot be easily oxidised

(5bii)
A white precipitate is formed with evolution of brown gas

(5biii)
(i) Hydrogen bond
(ii) Covalent bond

(5ci)
(i) Oxidation
(ii) Electrolysis

(5cii)
(i)Temperature
(ii)Concentration

(5ciii)
H₂SO₄ + 2NaOH ---> Na₂SO₄ +2H₂O
CaVa/CbVb = Na/NB
Va = CbVbna/Can
Va = 0.1251/0.52
Va = 2.5cm
==============================

(6ai)
Rate of a chemical reaction is defined as the number of moles of reactant converted or product formed per unit time.

(6aii)
Mass of CaCO3 = 3g
Molar mass of CaCO3=  100g/mol
No. of moles = 3/100 = 0.03
Time = 260 = 120s
Rate of reaction = No. of moles/Time
= 0.03/120 = 2.5 10-⁴

(6aiii)
(i) They are more resistant to corrosion
(ii) They are more durable
(iii) They have lower melting point

(6aiv)
2Pb(NO₃)₂ ---> 2PbO + 4NO₂ +O₂

(6bi)
I =Hard water=
(i)It has better taste than soft water
(ii) It can be supplied in lead pipes as it does not dissolve lead

II =Soft water=
(i) It does not deposit scale in boilers and fur in kettles
(ii) It does not waste soap

(6bii)
I - CO
II - SO₂

(6biii)
I - Hardness
II - Lustre appearance
III - Conductivity
IV - Ability to absorb

(6c)
4.3/2.12 = 142+18x/142
2.12(142+18x)/2.12 = 4.3*142/2.12
142+18x = 288
18x = 288-142
x = 146/18
x = 8
==============================

 

Related Topics

  Subject / Started by Replies Last post
0 Replies
602 Views
Last post July 14, 2021, 09:31:18 am
by NORTOLA
4 Replies
1082 Views
Last post June 08, 2022, 03:44:19 pm
by MANDINHO
2 Replies
253 Views
Last post July 07, 2022, 12:05:28 pm
by MANDINHO
2 Replies
391 Views
Last post July 18, 2022, 04:04:55 pm
by MANDINHO
2 Replies
258 Views
Last post July 20, 2022, 01:20:26 pm
by MANDINHO
4 Replies
575 Views
Last post July 21, 2022, 02:38:53 pm
by MANDINHO
3 Replies
190 Views
Last post July 22, 2022, 12:07:34 pm
by MANDINHO

Updated Topics

WAEC G E 2022 FURTHER MATHS ANSWERS (ESSAY & OBJ) by MANDINHO
Yesterday at 03:25:00 pm

WAEC GCE 2022 LITERATURE ANSWERS (DRAMA & POETRY) by MANDINHO
November 30, 2022, 04:28:04 pm

WAEC GCE 2022 MATHEMATICS ANSWERS (ESSAY & OBJ) by MANDINHO
November 26, 2022, 03:06:59 pm

Triple FACEBOOK REELs Views Using this! (**Earn $30 Per DAY**) FACEBOOK REELS Views by Wiz.gee
November 26, 2022, 06:14:15 am

NECO GCE 2022 AGRICULTURAL SCIENCE ANSWERS (PRACTICAL) by MANDINHO
November 24, 2022, 10:54:12 pm

New Dollar Arbitrage in Nigeria 2022 Method to Make Money with Dollar Arbitrage Business in Nigeria by Wiz.gee
November 23, 2022, 01:25:39 am

NECO GCE 2022 BIOLOGY ANSWERS (PRACTICAL) by MANDINHO
November 22, 2022, 09:59:35 pm


FBLike US on Facebook.. TWFollow US on Twitter..

Portal
Forum
RSS Feeds
FAQ
Members Intro
Announcements
Privacy Policy
Terms Of Use
Partners
About Us

Problem Solutions
Global News
Sports
Celebs
Politics
Gists In Town
General
Song Lyrics
Dating
Religion

Examination
Post-UTME/Admission
School News
Online Reading
Scholarship
Education
Entertainment
Download Links
Stories
Fashion

MTN NG
9Mobile NG
Airtel NG
Glo NG
World Networks
Pc Tweaks
Mobile Phone
Computer Tips
WebMaster
Programming

Browsing Cheats
Net Tricks
Health n Welfare
Latest Jobs
EarlyFace Group Of Nigeria 2022