Home EXAMS EXPO: WAEC Chemistry Questions and Answers 2022/2023

EXPO: WAEC Chemistry Questions and Answers 2022/2023

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EXPO: WAEC Chemistry Questions and Answers 2022/2023.

WAEC Chemistry Questions and Answers: This WAEC 2022 Chemistry expo question and answer is free for all candidates writing this year exams. If you are among those writing 2022 WAEC Examination, Feel free to expect free answer here.

WAEC Chemistry Questions and Answers

The West African Examinations Council is an examination that is for all the west African country (Ghana, Nigeria, Sierra Leone, Liberia, and Gambia).

Today’s WAEC Chemistry Question and Answers Expo (Theory and OBJ) – Monday, 6th June, 2022.

  • Chemistry 2 (Essay) › 13:00 hrs. – 15:00 hrs.
  • Chemistry 1 (Objective) › 15:00 hrs. – 16:00 hrs.

WAEC Chemistry Questions and Answers: Candidate that applied for the WAEC in any country should BOOKMARK this page for all and latest WAEC Chemistry exam expo.

Today’s WAEC Chemistry Practical Question and Answers Expo – Tuesday › 14th and Wednesday 22nd June, 2022.

WAEC 2022 CHEMISTRY PRACTICAL SPECIMEN
(1)
INSTRUCTIONS
(2)
In addition to the fittings and reagents normally found in a chemistry laboratory, the following apparatus and materials will be required by each candidate.
(a) One Burette of 50cm3 of capacity
(b) One pipette, either 20cm3 or 25cm3 (All candidates at one center must use pipettes of the same volume, these should be clean and free from grease).
(c) The usual apparatus for titration
(d) The usual apparatus and reagents for qualitative work including the following with all reagents appropriately labeled:

(i) 10% dilute sodium hydroxide solution
(ii) dilute hydrochloric acid
(iii) dilute trioxonitrate(v) acid
(iv) silver trioxonitrate(v) acid
(v) acidified potassium dichromate solution
(vi) aqueous ammonia
(vii) lime water
(viii) red and blue litmus paper
(ix) dilute tetraoxosulphate(vi)
(x) aqueous barium chloride
(e) Spatula
(f) Filtration apparatus,
(g) One beaker
(h) One boiling tube
(i) Four test tubes
(j) Starch solution indicator
(k) Glass rod
(l) Wash bottle containing distilled/deionized water,
(m) Burning splint,
👎 Watch glass
(o) Bunsen Burner/source of heat
(p) Droppers
(3)
(a) 150cm3 of iodine solution in a corked flask or bottle labeled ‘An’. These should all be the same containing 25.4g of I2 in 6.0g kl per dm3 of solution.

(b) 150cm3 of sodium thiosulphate pentahydrate solution in a corked flask or bottle labeled ‘Bn’. These should all be the same containing 24.82g of Na2S2O3 per dm3 of solution.
(c) One spatulaful of ammonium ferrous sulphate, (NH4)2Fe(SO4)2.6H2O in a specimen bottle labeled ‘Cn’.

Tuesday 14th June 2022

Chemistry 3 (Practical) (Alternative A) › 08:30 hrs. – 10:30 hrs. (1st Set)Chemistry 3 (Practical) (Alternative A) › 11:00 hrs. – 13:00 hrs. (2nd Set)Chemistry (Alternative D) (Alternative to Practical Work) **** ***** › 08:30 hrs. – 10:00 hrs.

Wednesday 22nd June 2022

  • Chemistry (Practical) (Alternative B) › 08:30 hrs. – 10:30 hrs. (1st Set)
  • Chemistry 3 (Practical) (Alternative B) › 11:00 hrs. – 13:00 hrs. (2nd Set)

CHEMISTRY ESSAY
ANSWERS
(1a)
A molecular formula consists of the chemical symbols for the constituent followed by numeric subscripts showing the number of atoms of each element present while structural formula consists of symbols for the atoms connected by short lines that represent chemical bonds.

(1b)
(i) Screening effect
(ii) Size of atom
(iii) Nuclear change

(1c)
(i) The reaction must proceed both forward and backward i.e reversible
(ii) DG = O

(1d)
(i) B
(ii) It has the least ionization energy among the three

(1e)
Graham’s law of diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of their densities provided other conditions remained constant

(1f)
(i) Na2SO4. Mg(NO3)2
(ii) CaCO3

(1g)
(i) Protein – Addition polymer
(ii) Perspex – Condensation polymer
(iii) Nylon – Condensation polymer

(1h)
Atomic radius can be defined as the half distance between the nucleus of two covalently bonded atoms.

(1i)
Ethanol has a higher boiling point than propane because it has stronger force of attraction than propane which has a weak van der waal’s force.

(1j)
(i) It aids the digestion of food
(ii) It aids the action of enzymes
(iii) It controls the availablity of nutrients

2ai)
(i) They have the same method of preparation
(ii) They have the same chemical properties

(2aii)
(i) Ethane has a single bond while Ethene has a double bond
(ii) They belong to different homogeneous series
(iii) They have different molecular formula and structural formula


(2bi)
(i)HCl
(ii) – It is colourless
– It has an irritating odour
(iii) 2Nacl(aq) + H2SO4(aq) —> Na2SO4(aq) + 2Hcl(g)

(3ai)
H2SO4 (aq) + 2KOH(aq) —> K2SO4(aq) + 2H2O(l)

(3aii)
Given, Va = 25.0cm³, Vb = 24.0cm³, Cb = 0.15mol/dm³, Ca =?, Na = 1 , Nb = 2
Using,
CaVa/CbVb = Na/Nb
Ca = CbVbNa/VaNb
Ca = 0.15 × 24.0 × 1/25.0×2
Ca = 3.6/50 = 0.072mol/dm³

(3bi)
(i) 2Mg(s) + CO2(g) —> 2MgO(aq) + C(g)
(ii) This is because magnesium can reduce carbon (iv) oxide to black carbon and producing magnesium oxide

 (3bii)
Mg(NO3)2
M of Mg(NO3)2 = 24+(2×14) + (6×16)
= 24 + 28 + 96
= 148g/mol
% of N = 28/148 × 100/1
N = 18.9%

(3ci)
(i) Reaction with KMnO4
(ii) Reaction with bromine water

(3cii)
It turns them colourless

(3d)
Boil the vegetable oil in sodium hydroxide solution, it breaks down releasing the organic acid and the alkanol. The process is known as saponification. The organic ester is immediately neutralized by the sodium hydroxide solution to form the sodium salt of the organic acid which is soap

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