WAEC Chemistry Practical Specimen 2024/2025

Are you preparing for the WAEC Chemistry Practical Examination for the year 2024/2025? Do you want to know what specimens you will need and how to use them effectively? If yes, then you are in the right place. In this blog post, we will provide you with a comprehensive guide on the WAEC Chemistry Practical Specimen 2024/2025, including the apparatus, materials, procedures, and tips for success. Read on to learn more.

What is the WAEC Chemistry Practical Examination?

The WAEC Chemistry Practical Examination is a crucial component of the West African Senior School Certificate Examination (WASSCE). It assesses your practical knowledge and laboratory skills in chemistry. To perform exceptionally well, you need to be well-prepared and acquainted with the specified specimens for the year 2024/2025.

The WAEC Chemistry Practical Examination consists of three questions, each carrying 25 marks. You will be required to answer two questions out of the three, within a duration of 2 hours and 30 minutes. The questions will be based on the following topics:

• Volumetric analysis
• Qualitative analysis
• Preparation of salts

You will be provided with the necessary apparatus and materials for each question, as well as instructions on how to conduct the experiments. You will also be expected to record your observations, calculations, and conclusions in a clear and logical manner.

What are the WAEC Chemistry Practical Specimen 2024/2025?

It is of utmost importance to ensure that the information contained in items 2 and 3 below does not reach the candidate either directly or indirectly before the examination. In addition to the standard fittings and reagents typically found in a chemistry laboratory, each candidate will require the following apparatus and materials:

• One burette with a capacity of 50 cm3.
• One pipette, either 20 cm3 or 25 cm3. (All candidates at a single center must use pipettes of the same volume, and these should be clean and free from any grease).
• The usual apparatus for titration.
• The usual apparatus and reagents for qualitative work, including the following with all reagents appropriately labeled:
  • (i) Dilute sodium hydroxide solution.
  • (ii) Dilute hydrochloric acid.
  • (iii) Dilute trioxonitrate (V) acid.
  • (iv) Silver trioxonitrate (V) solution.
  • (v) Acidified potassium dichromate solution.
  • (vi) Aqueous ammonia.
  • (vii) Lime water.
  • (viii) Red and blue litmus paper.
  • (ix) Dilute tetraoxosulphate (VI) acid.
  • (x) Fehlings solution A & B.
• Spatula.
• Filtration apparatus.
• One beaker.
• One boiling tube.
• Four test tubes.
• Methyl orange as an indicator.
• Glass rod.
• Wash bottle containing distilled/deionized water.
• Burning splint.
• Watch glass.
• Bunsen burner/source of heat.
• Droppers.
• Mathematical table/calculator.

Additionally, each candidate should be provided with the following items, where ‘n’ represents the candidate’s serial number:

• 150 cm3 of a solution of HCl in a corked flask or bottle labeled ‘An.’ All bottles labeled ‘An’ should contain the same solution, with a concentration of 8.5 cm3 of concentrated HCl per dm3 of solution. This solution is a strong acid commonly used in chemical laboratories for various experiments, including titration and acid-base reactions.
• 150 cm3 of Na2CO3·10H2O in a corked flask or bottle labeled ‘Bn.’ All bottles labeled ‘Bn’ should contain identical solutions with a concentration of 5.0 grams of the hydrated salt per dm3 of solution. This solution is a basic salt that can react with acids to produce carbon dioxide gas and water.
• One spatulaful of glucose in a specimen bottle labeled ‘Cn’. This must be the same for all candidates. Glucose is a simple sugar that can undergo oxidation and reduction reactions with various reagents, such as Fehlings solution and acidified potassium dichromate solution.
• One spatulaful of zinc oxide powder in a specimen bottle labeled ‘Dn’. This must be same for all candidates. Zinc oxide is a white solid that can react with acids and bases to form salts and water.

In all cases, more materials may be issued if required.

How to Conduct the WAEC Chemistry Practical Test – Instructions and Tips

Before you start the WAEC Chemistry Practical Test, you should read the instructions carefully and follow them strictly. Here are some general guidelines and tips to help you conduct the experiments successfully and efficiently:

• Wear appropriate protective clothing, such as gloves, goggles, and lab coat, to avoid any accidents or injuries.
• Handle all chemicals and apparatus with care and caution, and dispose of them properly after use.
• Use the droppers to transfer small volumes of liquids, and avoid spilling or wasting any reagents.
• Rinse the pipette and burette with distilled water before and after each use, and make sure they are free from any air bubbles or leaks.
• Use the wash bottle to rinse the glass rod, the inner walls of the conical flask, and the tip of the burette during titration, to ensure complete transfer of the solutions.
• Record the initial and final readings of the burette to the nearest 0.05 cm3, and calculate the average titre value from at least two concordant results (within 0.10 cm3 of each other).
• Use the mathematical table/calculator to perform any calculations, and show your working clearly and neatly.
• Record your observations in a tabular form, and use appropriate chemical equations and ionic equations to explain the reactions involved.
• State your inferences and conclusions based on your observations and calculations, and answer any questions related to the experiments.

Sample Questions and Answers

Here are some sample questions and answers based on the WAEC Chemistry Practical Specimen 2024/2025. You can use them as a model to practice and revise for your examination.

Question 1

You are provided with the following solutions:

• Solution A: 8.5 cm3 of concentrated HCl per dm3 of solution
• Solution B: 5.0 g of Na2CO3·10H2O per dm3 of solution

(a) Put A into the burette and titrate it against 25.0 cm3 portions of B using methyl orange as indicator. Repeat the titration to obtain consistent results. Tabulate your results and calculate the average volume of A used. The equation for the reaction is:

$$2HCl+Na2CO3\to 2NaCl+H2O+CO2$$

(b) From your results and the information provided, calculate the:

(i) concentration of A in mol/dm3

(ii) concentration of B in mol/dm3

(iii) number of moles of water of crystallization in B

© What is the colour change at the end point of the titration?

(d) Why is methyl orange a suitable indicator for this titration?

Answer 1

(a) Titration results:

Rough	1st	2nd	3rd
Final reading (cm3)	24.80	24.75	24.70
Initial reading (cm3)	0.00	0.05	0.00
Volume of A used (cm3)	24.80	24.70	24.70

Average volume of A used = (24.70 + 24.70 + 24.70) / 3 = 24.70 cm3

(b) (i) Concentration of A in mol/dm3

From the equation, 2 moles of HCl react with 1 mole of Na2CO3

Moles of HCl = Moles of Na2CO3 x 2

Moles of HCl = (Concentration of B x Volume of B) x 2

Concentration of B = 5.0 g/dm3

Molar mass of Na2CO3·10H2O = (23 x 2) + 12 + (16 x 3) + (10 x [(1 x 2) + 16]) = 286 g/mol

Moles of B = Mass of B / Molar mass of B

Moles of B = 5.0 / 286 = 0.0175 mol/dm3

Volume of B = 25.0 cm3 = 0.025 dm3

Moles of HCl = (0.0175 x 0.025) x 2 = 0.000875 mol

Concentration of HCl = Moles of HCl / Volume of HCl

Volume of HCl = 24.70 cm3 = 0.0247 dm3

Concentration of HCl =

 

To conclude, the WAEC Chemistry Practical Examination is a vital part of the WASSCE that tests your practical skills and knowledge in chemistry. You need to be familiar with the apparatus, materials, and procedures for the experiments, as well as the calculations, observations, and inferences involved. You also need to follow the instructions carefully and adhere to the safety precautions. By doing so, you can ace the examination and achieve your academic goals.

Here are some frequently asked questions and answers about the WAEC Chemistry Practical Specimen 2024/2025:

• Q: When will the WAEC Chemistry Practical Examination take place?
• A: The WAEC Chemistry Practical Examination is usually scheduled in the month of May or June, depending on the timetable for the year. You can check the official website of the West African Examinations Council (WAEC) for the latest updates and information.
• Q: How can I prepare for the WAEC Chemistry Practical Examination?
• A: You can prepare for the WAEC Chemistry Practical Examination by practicing with past questions and answers, revising the theoretical concepts and formulas, and familiarizing yourself with the specimens and apparatus. You can also consult your teachers, tutors, or peers for guidance and feedback.
• Q: What are the common mistakes to avoid in the WAEC Chemistry Practical Examination?
• A: Some of the common mistakes to avoid in the WAEC Chemistry Practical Examination are:
  • Not reading the instructions carefully and following them strictly.
  • Not rinsing the pipette and burette with distilled water before and after each use.
  • Not recording the initial and final readings of the burette to the nearest 0.05 cm3.
  • Not using the appropriate indicator for the titration.
  • Not writing the chemical equations and ionic equations correctly.
  • Not showing the working and units for the calculations.
  • Not stating the observations and inferences clearly and logically.
  • Not answering the questions related to the experiments.
• Q: How is the WAEC Chemistry Practical Examination graded?
• A: The WAEC Chemistry Practical Examination is graded based on the following criteria:
  • Accuracy and precision of the results and calculations.
  • Clarity and coherence of the observations and inferences.
  • Completeness and correctness of the chemical equations and ionic equations.
  • Relevance and quality of the answers to the questions.
  • Neatness and organization of the presentation.

The maximum score for each question is 25 marks, and the total score for the examination is 50 marks. The grade boundaries for the examination are determined by the WAEC and may vary from year to year.