Expo: WAEC Chemistry Questions and Answers 2022/2023 – theory / Objective

Free WAEC Chemistry Correct Questions and Answers for 2022 WASSCE Examination including the past and likely questions. Others are searching: Free WAEC Chemistry question and answer expo, verified WASSCE Chemistry exam, free WAEC runz.

WASSCE questions and answers for 2022/2023 are here. Are you a WAEC candidate? I’m very sure it’s a ‘yes‘. If so, your in the right place. This post will show you the WAEC verified Chemistry answers and the tricks you need to write and excel in your WAEC exam. So, stay on the site and Excel.

WAEC questions are set and compiled by the West African Senior School Certificate Examination Board (WASSCE). Make sure you follow the instructions below as provided by WAEC.

Examination Scheme – How it will Look like

There will be three papers, papers 1, 2 and 3 all of which must be taken. Papers 1 and 2 will be composite paper to be taken in one sitting.

PAPER 1

This will comprise fifty multiple-choice objective questions drawn from Section A of the syllabus. They will require candidates to answer all the questions within 1 hour for 50 marks.

PAPER 2

This will be a 2-hour essay paper covering the entire syllabus and carrying a maximum of 100 marks. The paper will be in two sections: Sections A and B.

Section A: This will comprise ten short structured questions drawn from the common portion of the syllabus (i.e. Section A of the syllabus). They will require candidates to answer all the questions for 25 marks.

Section B: This will comprise two questions from the common portion of the Syllabus (i.e. Section A of the syllabus) and two other questions from the Section of the syllabus which is peculiar to the country of the candidate (i.e. either) Section B or C of the syllabus).

They will require candidates to answer any three of the questions. Each question shall carry 25 marks.

2022/2023 WAEC Chemistry Essay and Objective Runz

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How Do I get 2022 Real WAEC Chemistry Questions and Answers – Expo

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This post contains both the Chemistry Objectives and the Theory.

Congratulations! WAEC chemistry answers are ready for you to use.

2022 Waec Chemistry Answers
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Theory-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)

(2ci)
Hydrocarbons are compounds having hydrogen and carbon atoms only. Examples are alkanes, alkenes, alkynes etc

(2cii)
(i) Coal
(ii) Crude oil

(2ciii)
C H
83% 100.83
83/12 17/1
6.92/6.92 17/6.92
1 2
Empirical formula = CH2

(2d)
[img]https://i.imgur.com/W1NMoXK.jpg[/img]
==============================

(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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Past questions

2022 WAEC Chemistry Theory Questions – Expo

(a) Two elements represented by the letters Q and R have atomic numbers 9 and 12, respectively.
(i) Write the electron configuration of R.
(ii) To what group does Q belong in the periodic table.
(iii) Write the formula of the compound formed when Q combines with R.
(iv) Explain briefly why Q is a good oxidizing agent.
(v) State whether R would be expected to form acidic or basic oxide.
(b) (i) State two assumptions of the kinetic theory of gases.
(ii) When some solids are heated, they change directly into the gaseous state. What name is given to this phenomenon?
(iii) List two substances that exhibit the phenomenon mentioned in (ii).
(iv) Write an expression to show the mathematical relationship between the rate of diffusion of a gas and its vapour.

2. An aqueous solution has a pH of 4.0.
(a) (i) What is the hydrogen ion concentration of the solution?
(ii) What effect will it have on litmus paper?
(iii) Which of the following salt solutions would have the same effect on litmus? Give a reason for your answer. NH4Cl(aq); NaCl(aq) ; CH3OON(aq).
(b) (i) Differentiate between a fine chemical and a heavy chemical.
(ii) Name two sources of air pollution.
(iii) Suggest one way of reducing air pollution in cities.

3. (a) (i) Explain briefly the fermentation process.
(ii) Write a balanced equation for the fermentation of glucose.
(iii) What substance must you add to the glucose solution to ferment it?
(iv) Explain briefly why tightly corked glass filled to the brim with palm wine shatters on standing.
(b) State one industrial application of each of the following methods of separation:
(i) Crystallization;
(ii) Fractional distillation.
(c) Explain the following terms:
(i) Saponification;
(ii) Esterification.
(d) Write a balanced equation to illustrate each of the terms in (c).
(e) i) What is hydrocarbon compound?
(ii) Name two principal sources of hydrocarbons.

Today’s WAEC Chemistry Objectives Answers – Expo

1-10 CBCDACDCCD

11-20 AADBDACBBC

21-30 BDDABDADAD

31-40 CDACCCCCDA

41-50 BBBCDCACDB

DISCLAIMER! These are not real WAEC Chemistry questions but likely repeated questions over the years to help candidate understand the nature of their examinations. Ensure to note every question provided on this page.

WAEC Chemistry likely questions and answers 2022

1. Identify the solid remaining when each of the following is heated.
(a) lithium trioxonitrate (V);
(b) potassium trioxonitrate (V);
(c) calcium trioxonitrate (V);

2. (a) When calcium oxide and coke are heated in a electric furnace, the roducts are carbon (ii) oxide and calcium carbide (CaC2), write the equation for this reaction.

(b) Addition of water to calcium carbide leads to the formation of calcium hydroxide and ethyne. Write the equation for the production of ethyne.

3. Calculate the percentage by mass of silicon tetrachloride. [2 marks]
4. Ammonia, NH3, and phosphine, Ph3, are the hydrides of the first two elements in group 5.
(a) Draw a dot and cross diagram for the ammonia molecule. [2 marks]
(b) Sketch and explain the shape of the ammonia molecule. [3 marks]

5. The first ionization energy of chlorine is +1260KJmol-1.
(a) Define the term first ionization energy.
(b) State and explain the general trend in the values of the first ionisation energy for the elements across the period, sodium to argon in the periodic table.

6. Compound A consisting of carbon and hydrogen only. The compound was found to contain 80% carbon by mass.
(a) Calculate the empirical formula of compound A using the data above.
(b) The relative molecular mass of compound A was found to be 30.
Use this information to deduce the molecular formula of compound A.
[H = 1.00 C = 12.00]

7. State two factors other than a change in temperature or the use of a catalyst that influence the rate of a chemical reaction.

How to Pass Waec Economics Examination Easily

To pass your WAEC successfully there are major things you have to do and they include the items below:

 Start reading early

Early reading is one the  basic factors of passing your WAEC exam. When you start reading early it’s always easier and simple.

Don’t wait for the examination period before you start reading. Start preparing on time to avoid preparing under pressure.

Download WAEC syllabus for Chemistry

Syllabus gives you the area of concentration in reading for your exam. In the same manner, WAEC syllabus helps you to know the area of concentration or topics which you should read. It also contains WAEC recommended textbooks and authors.

Download and Read WAEC Chemistry past questions and answers

Past questions and answers are of great help and it is something every examination candidate should not do without. Sometimes, questions are repeated or similar questions appear in your examination. The past question will enable you to have a clue of how to examination looks like.

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