WAEC Chemistry Practical Questions and Answers 2022/2023 – Complete Solution

WAEC Chemistry Practical examination is scheduled for 2022. Many WAEC applicants struggle to correctly answer the WAEC Practical Chemistry Alternative A and B questions. In this post, I will give you free access to the correct answers and also show you how to answer the 2022 WAEC Chemistry Practical questions correctly so you may get a decent result on your Chemistry exam.

Before tackling any questions, it is critical that you grasp the WAEC Chemistry Practical Making Scheme in order to present your answers in such a way that they would appeal to the examiner and get you high marks.

Bear it in mind that every single procedure is awarded marks. So, ensure you do not skip any step while reporting and presenting your practical results.

The Chemistry Practical question paper will consist of two sections and general Chemistry questions namely:

  1. Quantitative Analysis
  2. Qualitative Analysis

These involve titration and test of ions. You will be expected to carry out an experiment and report your inference and observation. What you will see will not be far from the WAEC Chemistry Specimen given to your school.

Note: Your titration endpoint will be given to you by your Chemistry teacher. It is not the same for every school but within a range.

Do not use the endpoint here. It may vary from your center endpoint but you can follow the calculation procedures.

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2022 WAEC Chemistry Practical Questions – Expo

WAEC Chemistry Practical Answers are not ready! School Isle will update this page with all the correct answers once its out.

(1a)
Volume of burrete = 50.00cm³
Volume of pipette = 25.00cm³
Indicator = Methyl orange

TABULATE

Final burette readings (cm³); 37.50 | 22.50 | 37.50 | 44.50

Initial burette readings(cm³); 0.00 | 0.00 | 0.00 | 0.00

Volume f Acid used (cm³); 37.50 | 22.50 | 22.50 | 22.50

Volume of A used = 1st + 2nd + 3rd/3
= 22.50+22.50+22.50/3
Average volume of A used = 22.50cm³

(1bi)
Concentration of A ( CA )?
2.03g in 500cm³ of solution

Volume = 500cm³/1000 = 0.500dm³
In g/dm³ = 2.03/0.5 = 4.06g/dm³

To find concentration in mol/dm³
Conc. of A in mol/dm³ = Conc. of A in g/dm³/Molar mass

Conc. of A in mol/dm³ = 4.06/36.5
= 0.1112mol/dm³
Molar mass of A (HCL) = 1+35.5 = 36.5g/mol

(1bii)
Number of mole of the Acid in average titre
Na = CaVa
= 0.1112 × 22.50
= 2.52moles

(1biii)
Nb= ? Na= 3, Ca= 0.1112mol/dm³, Cb = 0.12mol/dm³ , Va = 22.50cm³, Vb = 50.00cm³

CaVa/CbVb= nA/nB

0.1112×22.50/0.12×50 = 3/nB

nB × 2.502 = 18
nB = 18/2.502 =
:. nB = 7.194moles
= 7moles(approx.)

(1biv)
Mole ratio of Acid to base
nA:nB = 7:3

(2a)
Test; C + 10cm³ of distilled water + filter

Observation; C dissolves partially to give a light green solution. Blue filtrate and green residue

Inference; C is a mixture of soluble and insoluble salt

(2bi)
Test; 2cm³ of filtrate + NaOH in drops in excess

Observation; Blue precipitate remains

Inference; CU²+ is present

(2bii)
Test; 2bi + warm

Observation; a colourless gas with a chocking smell which turns moist red litmus blue and forms dense white fumes with hydrogen chloride gas

Inference; NH³ from NH⁴+

(2biii)
Test; 2cm³ of filtrate + BaCl² + excess HCl

Observation; white precipitate, precipitate Remains

Inference; SO²- CO3²- or SO4²- is present, SO4²- confirmed

(2ci)
Test; Residue + HNOg

Observations; effervescence of a colourless and odourless gas which turns like water milky and turns moist blue to litmus red

Inference; CO2 from CO3²-

(2cii)
Test; 2ci + NH3 in drops in excess

Observations; blue precipitate. Precipitate dissolved to give a deep blue solution

Inference; CU2+ present
CU2+ confirmed

(3ai)
The value will increase

(3aii)
The occur as a result of the decrease in the concentration of base due to the added volume of water

(3bi)
There will be no visible reaction because copper is less than Zinc in the electrochemical series

(3bii)
It absorb water and become sticky because it is hygroscopic

(3biii)
The solution turns pink

(3c)

When NaOH is added to the solution of zn³+, a white precipitate is formed which later dissolve in excess NaOH due to the formation of zinc hydroxide

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Chemistry Practical past questions 2021

All your burette readings (initials and final) as well as the size of your pipette must be recorded but no account experiment procedure is required. all calculations must be done in your answer booklet.

1. A is a solution of potassium tetraoxomanganate (VII). B is a solution of iron (II) Chloride containing 4.80 g of the salt in 250cm3 of solution. (a) Put A into the burette. Pipette 20.0cm3 or 25.0 of B into a conical flask, add 20.0cm3 of H2SO4(aq)and titrate  with A. repeat the titration to obtain concordant titire values. Tabulate your results and calculate the average volume of A used. The equation of the reaction is: MnO4(aq) + 5Fe2+(aq) + 8H+(aq) > Mn2+(aq) + 5Fe3+(aq) + 4H2O(I)

(b) From your results and the information provided, calculate the (i) concentration of B in moldm-3; (ii) Concentration of A in moldm-3 (iii) number of moles of Fe2+ in the volume of B pipetted [FeCI2 = 127 gmol-1] Credit will be given for strict adherence to the illustrations for observations precisely and for accurate inferences. all tests, observations and inferences must be clearly entered in the booklet in ink at the time they are made.

2.  C and D are inorganic salts. Carry out the following exercises on them. Record your observations and identify any gas(es) evolved. State the conclusions and draw fromt the result  of each test. (a) Put all of C in a test tube and add about 5cm3 of distilled water. Shake thoroughly and test the resulting solution with litmus paper. Divide the solution into three portions. (i) To the first portion, add NaOH(aq) in drops, then in excess. (ii) To the second portion, add NH3(aq) in drops, then in excess. (iii) To the third portion, add AgNO3(aq) followed by HCI(aq) (b)(i) Put all of D in a test tube and add about 5cm3 of distilled water. Shake thoroughly and feel the test tube. (ii) To about 2cm3 of the solution, add HCI(aq).

3. State the observations that would be made when each of the following reactions are carried out in the laboratory (a) Addition of 2cmof bench H2SO4(aq) to 2cm3 of barrium chloride solution; (b) Addition of 2cm3 of dilute hydrochloric acid to 1 g of powered iron(II) sulphide (FeS); (c) Addition of 2cm3 of dilute hydrochloric acid to 1 g of iron filings and allowed to stand for sometime.

Today’s 2022 WAEC Chemistry Correct Answers – Expo

1. Equation of the reaction: MnO4(aq) + 5Fe2+(aq) + 8H+(aq) > Mn2+(aq) + 5Fe3+(aq) + 4H2O(I)

The questions above are strictly for practice not tomorrow’s Chemistry expo.

Note: The 2022 WAEC Chemistry Practical answers will be posted here 2 hours before your examination for free. Do not forget to reload this page in order to see the answers. Also join our WatsApp Group for more updates.

(2021 Answers)

(1a)
Burette reading (cm)³|1st reading|2na Reading|3rd reading|
Final |15.25|30.53|45.79|
Initial |0.00|15.25|30.53|
Volume of acids used |15.25|15.28|15.26

Average volume of acid used =15.25+15.26/2
=15.255cm³
=15.26cm³
Or =15.27cm³

(1b)
Given; mass con of A =5g/500cm³ = 5g/0.5dn³
CA=10g/dm³
A is HNO3
Therefore molar mass =1+14+(16*3)=15+48=63g/mol¹

Molarity of A = gram con/molar mass
CA=10/63=0.1587mol/dm3

(1bii)
Using CAVA/CBVB =Na/NB
With reacting equation ; HNO³ + NaOH—NaNO3+H2O
nA=1 nB=1
0.1587*15.26/CB*25.00=1/1
25CB=0.1587*15.26
CB=0.1587*15.26/25
CB=0.09687mol/dm³

(1biii)
B is NaOH
Molar mass
23+16+1=40g/mol
Conc of B in g/dm³=molarity * molar mass
= 0.09687*40
=3.8748g/dm³

(1biv)
No of moles present in 250cm³ of NaOH is =molar conc * volume
=0.09687*250/1000
=0.0242moles
Mole ratio of NaOH and NaNO3 is 1;1
No; of mole of NaNO3 which reacted is 0.0242
Mass of NaNO3 formed =molar mass * no; of moles
=85*0.0242
=2.05grams
=====================================

(2a)
TEST: C+burning splint

OBSERVATION: Sample C burst into flame .It burns with non smoky blue flame without soot. Colorless gas that turns wet blue litmus paper faint red and turns like water milky is present.

INFERENCE: C is volatile and flammable. The gas is CO2 from combustion of saturated organic compound.

(2bi)
TEST: C + distilled water + shake

OBSERVATION: Clear or colorless solution is observed

INFERENCE: C is miscible with water

(2bii)
TEST: C + Acidified K2Cr207

OBSERVATION: Orange color of K2Cr207 solution turns pale green and eventually pale blue on cooling

INFERENCE: C is a reducing agent

(2C)
TEST: D + C + 10% NaOH + Shake

OBSERVATION: D dissolves slowly in C and produces reddish brown solution. Reddish brown solution turns yellow precipitate. The precipitate has an antiseptic odour
INFERENCE: D is soluble in organic solvents

(2d)
Compound belongs to the class of secondary alkanol
=====================================

3ai)

oxygen

(3c)

It turns blue litmus paper red.

3d

Pure copper(II) sulfate is white. It is also known as anhydrous copper(II) sulfate because it has no water in it. When water is present in a sample of copper(II) sulfate it turns blue. … This colour change can be used to detect the presence of water (or water vapour).

3c(i)

When exposed to light, silver chloride decomposes into gray metallic silver and chlorine. The light sensitivity of the silver chloride and other silver halides, such as silver bromide and silver iodide, forms the basis of the photographic process.

3bi

Phenolphtalein is chosen because it changes color in a pH range between 8.3 – 10. It will appear pink in basic solutions and clear in acidic solutions.

3c(i)

When exposed to light, silver chloride decomposes into gray metallic silver and chlorine. The light sensitivity of the silver chloride and other silver halides, such as silver bromide and silver iodide, forms the basis of the photographic process.

3cii

The ammonia combines with silver ions to produce a complex ion called the diamminesilver(I) ion, [Ag(NH3)2]+. This is a reversible reaction, but the complex is very stable, and the position of equilibrium lies well to the right.

3d

Pure copper(II) sulfate is white. It is also known as anhydrous copper(II) sulfate because it has no water in it. When water is present in a sample of copper(II) sulfate it turns blue. … This colour change can be used to detect the presence of water (or water vapour).

WAEC chemistry Practical likely questions and answers

The WASSCE chemistry possible questions and answers most times come from the past questions and answers. I recommend you read the past questions above and also follow the WAEC chemistry Syllabus.

IMPORTANT: To avoid being a scapegoat, use your school’s endpoints. Your teacher will be the one to report, and any endpoint he reports will be considered accurate. While you’re copying, make sure your eyes are bright. Best wishes.

If you have any question, do well to drop a comment below.

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