WAEC Chemistry Practical Questions and Answers 2022/2023 (Complete Solution)

It is pertinent you recognize the WAEC Chemistry Practical making scheme earlier than trying any questions with the intention to gift your solutions in this sort of manner that it’s going to appearance appealing to the examiner to earn you huge marks.

Bear in thoughts that each unmarried system is presented marks. So, make sure you do now no longer bypass any step whilst reporting and imparting your realistic effects.

 

The Chemistry Practical query paper will include sections and trendy Chemistry questions namely:

 

Quantitative Analysis

Qualitative Analysis

These contain titration and check of ions. You may be predicted to perform an test and record your inference and observation. What you may see will now no longer be a ways from the WAEC Chemistry Specimen given in your faculty.

 

 

Note: Your titration endpoint may be given to you with the aid of using your Chemistry instructor. It isn’t the identical for each faculty however inside a variety.

 

Do now no longer use the endpoint right here. It can also additionally range out of your middle endpoint however you could observe the calculation procedures.

 

See:

 

WAEC Physics Practical

Check WAEC Timetable to recognize the following exam

WAEC Biology Practical

WAEC Economics Answers

WAEC Practical Chemistry Questions and Answers (Expo)

 

3ai)The price will increase

 

(3aii)The arise because of the lower withinside the attention of base because of the delivered extent of water

 

(3bi)There may be no seen response due to the fact copper is much less than Zinc withinside the electrochemical series

 

 

(3bii)It take in water and turn out to be sticky due to the fact it’s miles hygroscopic(3biii)The answer turns crimson

 

(3c)When NaOH is delivered to the answer of zn³+, a white precipitate is shaped which later dissolve in extra NaOH because of the formation of zinc 

 

All your burette readings (initials and final) in addition to the scale of your pipette have to be recorded however no account test system is required. all calculations have to be completed to your solution guide.

 

1. A is an answer of potassium tetraoxomanganate (VII). B is an answer of iron (II) Chloride containing four.eighty g of the salt in 250cm3 of answer. (a) Put A into the burette. Pipette 20.0cm3 or 25.zero of B right into a conical flask, upload 20.0cm3 of H2SO4(aq)and titrate  with A. repeat the titration to acquire concordant titire values. Tabulate your effects and calculate the common extent of A used. The equation of the response is: MnO–four(aq) + 5Fe2+(aq) + 8H+(aq) > Mn2+(aq) + 5Fe3+(aq) + 4H2O(I)

 

(b) From your effects and the records provided, calculate the (i) attention of B in moldm-3; (ii) Concentration of A in moldm-3 (iii) wide variety of moles of Fe2+ withinside the extent of B pipetted [FeCI2 = 127 gmol-1] Credit may be given for strict adherence to the illustrations for observations exactly and for correct inferences. all tests, observations and inferences have to be without a doubt entered withinside the guide in ink on the time they’re made.

 

2.  C and D are inorganic salts. Carry out the subsequent sports on them. Record your observations and perceive any fueloline(es) evolved. State the conclusions and draw fromt the result  of every check. (a) Put all of C in a check tube and upload approximately 5cm3 of distilled water. Shake very well and check the ensuing answer with litmus paper. Divide the answer into 3 portions. (i) To the primary portion, upload NaOH(aq) in drops, then in extra. (ii) To the second one portion, upload NH3(aq) in drops, then in extra. (iii) To the 0.33 portion, upload AgNO3(aq) accompanied with the aid of using HCI(aq) (b)(i) Put all of D in a check tube and upload approximately 5cm3 of distilled water. Shake very well and sense the check tube. (ii) To approximately 2cm3 of the answer, upload HCI(aq).

 

 

3. State the observations that might be made whilst every of the subsequent reactions are performed withinside the laboratory (a) Addition of 2cm3 of bench H2SO4(aq) to 2cm3 of barrium chloride answer; (b) Addition of 2cm3 of dilute hydrochloric acid to one g of powered iron(II) sulphide (FeS); (c) Addition of 2cm3 of dilute hydrochloric acid to one g of iron filings and allowed to face for sometime.

 

ANSWERS

 

1. Equation of the response: MnO–four(aq) + 5Fe2+(aq) + 8H+(aq) > Mn2+(aq) + 5Fe3+(aq) + 4H2O(I)

 

The questions above are strictly for practice, now no longer tomorrow’s Chemistry expo.

 

More solutions and the 2022 WAEC Chemistry questions and solutions loading…

 

Note: The 2022 WAEC Chemistry Practical solutions may be published right here at some stage in the WAEC Practical Chemistry exam. Keep checking and reloading this web page to recognize whilst the solutions are published. Do now no longer overlook to reload this web page so one can see the solutions.

 

Today’s Practical Chemistry Answers

 

(2020 Answers)

 

3ai)

oxygen

 

(3c)

 

It turns blue litmus paper crimson.

 

3d

Pure copper(II) sulfate is white. It is likewise referred to as anhydrous copper(II) sulfate as it has no water in it. When water is found in a pattern of copper(II) sulfate it turns blue. … This shadeation extrade may be used to locate the presence of water (or water vapour).

 

3c(i)

When uncovered to mild, silver chloride decomposes into grey steel silver and chlorine. The mild sensitivity of the silver chloride and different silver halides, consisting of silver bromide and silver iodide, paperwork the premise of the photographic process.

 

3bi()

 

Phenolphtalein is selected as it modifications colour in a pH variety among 8.3 – 10. It will seem crimson in simple answers and clean in acidic answers. ..

 

3c(i)

When uncovered to mild, silver chloride decomposes into grey steel silver and chlorine. The mild sensitivity of the silver chloride and different silver halides, consisting of silver bromide and silver iodide, paperwork the premise of the photographic process.

 

3cii

The ammonia combines with silver ions to provide a complicated ion known as the diamminesilver(I) ion, [Ag(NH3)2]+. This is a reversible response, however the complicated may be very stable, and the placement of equilibrium lies nicely to the right.

 

3d

Pure copper(II) sulfate is white. It is likewise referred to as anhydrous copper(II) sulfate as it has no water in it. When water is found in a pattern of copper(II) sulfate it turns blue. … This shadeation extrade may be used to locate the presence of water (or water vapour).

 

Remember What I instructed you: Use your faculty endpoints to keep away from being a scapegoat. Your instructor may be the only to record, any endpoint said with the aid of using him may be taken as an correct result. Shine your eyes whilst copying. Goodluck

 

 

(1a)

Burette reading (cm)³|1st reading|2na Reading|third reading|

Final |15.25|30.53|45.79|

Initial |zero.00|15.25|30.53|

Volume of acids used |15.25|15.28|15.26

 

Average extent of acid used =15.25+15.26/2

=15.255cm³

=15.26cm³

Or =15.27cm³

 

(1b)

Given; mass con of A =5g/500cm³ = 5g/zero.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=zero.1587mol/dm3

 

(1bii)

Using CAVA/CBVB =Na/NB

With reacting equation ; HNO³ + NaOH—NaNO3+H2O

nA=1 nB=1

zero.1587*15.26/CB*25.00=1/1

25CB=zero.1587*15.26

CB=zero.1587*15.26/25

CB=zero.09687mol/dm³

 

(1biii)

B is NaOH

Molar mass

23+16+1=40g/mol

Conc of B in g/dm³=molarity * molar mass

= zero.09687*40

=3.8748g/dm³

 

 

(1biv)

No of moles found in 250cm³ of NaOH is =molar conc * extent

=zero.09687*250/1000

=zero.0242moles

Mole ratio of NaOH and NaNO3 is 1;1

No; of mole of NaNO3 which reacted is zero.0242

Mass of NaNO3 shaped =molar mass * no; of moles

=85*zero.0242

=2.05grams

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

 

(2a)

TEST: C+burning splint

 

OBSERVATION: Sample C burst into flame .It burns with non smoky blue flame with out soot. Colorless fueloline that turns moist blue litmus paper faint crimson and turns like water milky is gift.

 

INFERENCE: C is unstable and flammable. The fueloline is CO2 from combustion of saturated natural compound.

 

(2bi)

TEST: C + distilled water + shake

 

OBSERVATION: Clear or colorless answer is observed

 

INFERENCE: C is miscible with water

 

(2bii)

TEST: C + Acidified K2Cr207

 

OBSERVATION: Orange colour of K2Cr207 answer turns light inexperienced and ultimately light blue on cooling

 

INFERENCE: C is a decreasing agent

 

(2C)

TEST: D + C + 10% NaOH + Shake

 

OBSERVATION: D dissolves slowly in C and produces reddish brown answer. Reddish brown answer turns yellow precipitate. The precipitate has an antiseptic odour

INFERENCE: D is soluble in natural solvents

 

(2d)

Compound belongs to the magnificence of secondary alkanol

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

(3ai)

Zinc nitrate

 

(3aii)

2 Zn(NO 3 )2 —–>2 ZnO + four NO 2 + O 2

 

(3aiii)

aIt turns white whilst bloodless from it yellow shadeation whilst it became hot

 

(3b)

Pipette / degree 50.0cm3 of the inventory answer right into a 250

cm3 volumetric flask (containing a few distilled water). Shake / swirl and upload greater distilled water till the mark is reached.

 

(3c)

Al2(SO4)3 – turns blue litmus crimson

 

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