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Showing posts from April, 2023

Full CBT Rollout for SSCE Postponed to 2027 by WAEC

 Abuja — The West African Examinations Council (WAEC) has postponed the full implementation of the computer-based test (CBT) format for the 2026 Senior School Certificate Examination (SSCE) until 2027, according to a statement released at the council’s 63rd annual meeting in Umuahia, Abia State.  Hajia Binta Abdulkadir, Chairman of WAEC’s Nigeria National Committee, explained that the 2026 May/June edition will now serve as a pilot phase — allowing candidates to sit for either the traditional paper-and-pen test or the digital format. She emphasized that no student will be disadvantaged by the transition.  The delay follows widespread concern over the readiness of many schools, particularly in rural areas, for full digital exams. Many institutions lack adequate computers, reliable electricity, internet connectivity, and trained personnel—factors WAEC and the Federal Ministry of Education say are essential for a successful rollout.  To facilitate the switch, WAEC co...

WAEC 2023 Exams Preparatory Class on the Analysis of Lead Trioxonitrate V

      The analysis of lead trioxonitrate V can be done using different tests to help identify the ions present in the compound.    This tutorial class will be based on one of the several methods of testing for the ions in lead trioxonitrate V salt.   Procedure:   Put some lead trioxonitrate V salt sample into a test tube and add about 10 cm 3 of distilled water, then shake very well to dissolve. Divide the solution into five portions. 1.      To the first portion, add dilute sodium hydroxide solution in drops then excess. A white precipitate which is soluble in excess dilute sodium hydroxide indicates that zinc ions, aluminium ions or lead ions might be present in the solution.   2.       Add aqueous ammonia in drops then in excess to the second portion. A white precipitate is formed which is insoluble in excess aqueous ammonia indicating that zinc ions are absent and aluminium ions or lead...

Stoichiometry Tutorial Step by Step

  Stoichiometry is the study of the quantity of the reactants and products involved in a chemical reaction. It can also be defined as the determination of the ratio in which elements or compounds react with one another in a chemical reaction. Method Calculating Stoichiometric Problems In stoichiometric calculation, the basic method of calculating the problems is by converting one quantity to another using the conversion factors which are usually found in a balanced chemical equation. These conversion factors are the important ratios which can be turned into a fraction to produce the desired results. The molar mass of a substance is one of the important conversion units which is defined as the mass of one mole of a substance expressed in grams. Types of Stoichiometry Calculations or Problems There are four basic types of stoichiometry calculations which include: 1.        Mass-to-mass conversion 2.        Mass...

Faraday's Laws of electrolysis

  Faraday’s Laws of Electrolysis Faraday put forward two laws of electrolysis and he also discovered from his experiment that the quantity of products of electrolysis depends on the following Time of the flow of electric current The ionic charge of the element deposited The amount of current Faraday’s First Law of Electrolysis The first law states that the amount of the element deposited during electrolysis is directly proportional to the quantity of electricity passed through the electrolyte (electrolytic solution). Mathematically       M ∞ Q Where  Q = quantity of electricity measured in Coulomb M = mass of the substance deposited Since the quantity of electricity is given by Q = current x time in seconds Faraday’s first law can also be stated as “the mass of element deposited during an electrolysis is proportional to the size of the current and the time taken for the flow of the current.”    M ∞ I x t  Or  M = є I t Where є ...