MATSEC IM Chemistry case studies
MATSEC IM Chemistry · Put your knowledge to work in context.
MATSEC Intermediate Matriculation (IM) Chemistry is one of the subject examinations offered at the IM level by the MATSEC Examinations Board, which operates within the University of Malta at Msida. The board lists subject syllabi for four levels - SEC (Secondary Education Certificate), SEAC (Secondary Education Applied Certificate), IM (Intermediate Matriculation) and AM (Advanced Matriculation) - and publishes syllabus documents year by year. The MATSEC IM Chemistry case studies are 5 cases and about 3,697 words.
1Standard solution and an acid titration: which error actually matters?
A candidate must prepare 250.0 cm³ of a standard solution of anhydrous sodium carbonate of concentration 0.0500 mol dm⁻³ (M = 106 g mol⁻¹) and use it to find the concentration of a hydrochloric acid solution. She weighs 1.33 g of the solid on a balance reading to two decimal places, dissolves it in a beaker and transfers the solution to a 250 cm³ volumetric flask, rinsing the beaker twice into the flask before making up to the mark and inverting several times.
631 words, about 3 min2Enthalpy of combustion of ethanol: interpreting a value that is far too small
A student determines the enthalpy change of combustion of ethanol using a spirit burner beneath a copper can holding 100.0 g of water. The water temperature rises from 21.5 °C to 47.9 °C.
688 words, about 3 min3Ammonia plant: yield versus rate when changing conditions
An ammonia plant runs N₂(g) + 3H₂(g) ⇌ 2NH₃(g), ΔH = −92 kJ mol⁻¹, over an iron catalyst at 450 °C and 200 atm. At these conditions the gas leaving the reactor contains about 35% ammonia by volume.
805 words, about 4 min4Identifying four unlabelled liquids: when one positive test is not enough
A technician finds four unlabelled bottles of colourless liquids in a school store cupboard, marked only A, B, C and D. The stock list says they are ethanoic acid, ethanol, ethanal and propanone, but does not say which is which.
763 words, about 4 min5Cell potentials, predictions and a voltmeter that reads low
A student is given these standard electrode potentials: Zn²⁺/Zn = −0.76 V, Fe²⁺/Fe = −0.44 V, Cu²⁺/Cu = +0.34 V, Ag⁺/Ag = +0.80 V. She builds a cell from a zinc strip in 0.10 mol dm⁻³ zinc sulfate and a copper strip in 0.10 mol dm⁻³ copper sulfate, joined by a salt bridge, and connects a high-resistance voltmeter.
810 words, about 4 min