NCEA L2 Chemistry case studies
NCEA L2 Chemistry · Put your knowledge to work in context.
NCEA Level 2 Chemistry is the second-year chemistry offering within New Zealand's National Certificate of Educational Achievement, administered by the New Zealand Qualifications Authority (NZQA). It is aimed at secondary students who have completed Level 1 science learning and want a deeper, more quantitative treatment of chemistry before Level 3 or tertiary study. This page is an independent study resource; it is not affiliated with or endorsed by NZQA. The subject is described by NZQA as the scientific study of the properties of different substances and how those substances can change. The NCEA L2 Chemistry case studies are 5 cases and about 1,967 words.
1Limiting reagent in an impure copper(II) oxide preparation
At a school senior chemistry practical, a student makes copper(II) sulfate crystals from copper(II) oxide that is contaminated with sand. The student weighs 5.00 g of the impure oxide, labelled as containing 8.0% inert sand by mass, and adds it to 40.0 mL of 1.50 mol L−1 sulfuric acid.
415 words, about 2 min2Cobalt chloride equilibrium and colour changes
A student investigates the equilibrium between pink hydrated cobalt(II) ions and blue tetrachlorocobaltate(II) ions: [Co(H2O)6]2+(aq) + 4Cl−(aq) ⇌ CoCl4^2−(aq) + 6H2O(l). A pink solution is made by dissolving a small amount of cobalt(II) chloride in water.
405 words, about 2 min3Ethyl ethanoate synthesis: yield and separation decisions
A Level 2 student prepares ethyl ethanoate in a school laboratory. They mix 10.0 mL of ethanol (density 0.789 g mL−1) with 10.0 mL of ethanoic acid (density 1.05 g mL−1) and add 2.0 mL of concentrated sulfuric acid.
386 words, about 2 min4Sacrificial protection versus tin coating on a coastal bridge
A coastal footbridge has steel bolts. One set is galvanised with zinc; another is electroplated with tin.
423 words, about 2 min5Indicator choice in a weak base–strong acid titration
A student standardises a solution of hydrochloric acid using 0.120 mol L−1 ammonia solution. Ammonia is a weak base: NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH−(aq).
338 words, about 2 min