CSEC Chemistry case studies
CSEC Chemistry · Put your knowledge to work in context.
CSEC® Chemistry is a Caribbean Examinations Council (CXC®) subject qualification at the Caribbean Secondary Education Certificate level, listed by CXC® alongside other CSEC® and CAPE® subjects. It is intended for secondary-school candidates across the Caribbean region who are building a foundation in chemistry and who may go on to advanced study or science-related careers. The CSEC Chemistry case studies are 5 cases and about 3,035 words.
1Hydrated Copper(II) Sulphate: When Strong Heating Destroys the Evidence
A student is determining the value of x in CuSO₄·xH₂O. She weighs a clean, dry crucible with its lid: 23.46 g.
561 words, about 3 min2Vinegar Titration: A Label Claim and a Persistent Bias
A student analyses a local brand of vinegar labelled '5.0 g ethanoic acid per 100 cm³'. She pipettes 25.0 cm³ of the vinegar into a 250 cm³ volumetric flask and makes the mark with distilled water.
636 words, about 3 min3Nickel Electroplating: Current, Efficiency and Coating Quality
A small workshop electroplates steel spoons with nickel. The electrolyte is nickel(II) sulphate solution, the anodes are pure nickel, and each spoon is polished, degreased and weighed before plating.
589 words, about 3 min4Thiosulphate Clock Reaction: An Anomalous Run
A student investigates how the concentration of sodium thiosulphate affects the rate of its reaction with dilute hydrochloric acid. Each trial uses 5.0 cm³ of 1.0 mol dm⁻³ HCl and enough distilled water to make a total volume of 50.0 cm³, with sodium thiosulphate solution of concentration 1.0 mol dm⁻³.
692 words, about 3 min5Molasses Fermentation: Yield, Losses and a Yeast Sales Claim
A small distillery ferments molasses. In a trial, 500 kg of sucrose (C₁₂H₂₂O₁₁) is hydrolysed with water and fermented according to the overall equations: C₁₂H₂₂O₁₁ + H₂O → 2 C₆H₁₂O₆ C₆H₁₂O₆ → 2 C₂H₅OH + 2 CO₂ After fermentation and distillation, 200 kg of ethanol is collected.
557 words, about 3 min