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Showing posts from October, 2021

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...

Quantitative Analysis

  Quantitative analysis deals with the determination of the amount of each component in a sample of matter. It is divided into two which include: a.    Gravimetric analysis b.    Volumetric analysis Gravimetric analysis : is interested in the measurement of mass of the substances. Volumetric analysis : is interested in the measurement of the volume of solutions.   Titration is the method used in volumetric analysis. This is done by careful addition of standard solution from a graduated container until the reaction is complete. A complete reaction is indicated by a colour change in the resulting solution. Some apparatus used for volumetric analysis These are burette, pipette, conical flask, beaker, funnel, wash bottle and volumetric flask. Standard solution is a solution of a known concentration. Basic Principles of Volumetric Analysis   Test substance or analyte, is normally a base in acid-base titration, is pipetted into the co...

How to Identify the Ions in Aluminium Chloride Salt

Aluminium chloride is white crystal solid. It is very soluble in water and it hydrolyses in water to form acidic solution. The ease with which the anhydrous salt hydrolyses explains why hydrogen chloride fumes are evolved from it in damp air. Aluminium chloride is a covalent compound which reacts with water. The two ions in the compound are aluminium ion and Chloride ion. How to identify the Aluminium ion (cation) 1.     Test with sodium hydroxide : add a few drops sodium hydroxide solution to the solution the unknown salt. The formation of a white gelatinous precipitate which dissolves in excess sodium hydroxide solution shows that aluminium ion is present. Note: lead ions and zinc ions give similar reactions so this may not be the final test. 2.     Test with aqueous ammonia : add a few drops of aqueous ammonia to the unknown salt solution; the formation of a white gelatinous precipitate which is insoluble in excess aqueous ammonia confirms the p...

Qualitative Analysis of inorganic Compound

  This is a type analysis which involves the identification of the ions ( cation and anion) in a given inorganic substance. Thus, Qualitative analysis deals with the identification of the compound. To effectively identify the ions, it is necessary to be able to observe the presence of any chemical reaction which is normally recognized by ·         Colour change ·         Evolution of gas ·         Precipitation      Colour Change : colour change is associated with transition metal ions. The major cause of the colour in transition metal ions is electronic transition within the d-block level. The colour of light which show, is the colour of light which is reflected by the ion. This change of transition metal ions is common when they form a bond with water or ammonia. It is important to note that zinc does not form coloured ion, this is because zinc ...