IB Chemistry HL case studies
IB Chemistry HL · Put your knowledge to work in context.
IB Chemistry HL is the higher-level chemistry course within the International Baccalaureate Diploma Programme, a two-year pre-university qualification taught in schools worldwide and recognised by universities for admission and, in some cases, credit. It suits students who want a rigorous, experimentally grounded chemistry foundation: strong algebra, comfort with moles and stoichiometry, and willingness to explain reasoning rather than recall facts. The IB Chemistry HL case studies are 5 cases and about 2,757 words.
1Born-Haber versus theoretical lattice enthalpy of silver chloride
A student is investigating the bonding in silver chloride. She has the following data: standard enthalpy of formation of AgCl(s) = -127 kJ mol-1; enthalpy of atomisation of Ag(s) = +285 kJ mol-1; first ionisation energy of Ag(g) = +731 kJ mol-1; bond dissociation enthalpy of Cl2(g) = +242 kJ mol-1; electron affinity of Cl(g) = -349 kJ mol-1.
517 words, about 3 min2Kinetics of the hydrogen peroxide-iodide reaction
A student studies the reaction between hydrogen peroxide and iodide ions in acidic solution: H2O2(aq) + 2H+(aq) + 2I-(aq) - I2(aq) + 2H2O(l). She measures initial rates by timing the appearance of a blue-black colour with starch.
551 words, about 3 min3Enthalpy of combustion of methanol by spirit burner
A student determines the enthalpy of combustion of methanol using a spirit burner. She places 100.0 g of water in a copper can, records the initial temperature as 21.0 C, burns methanol until the temperature reaches 46.0 C, and finds the burner has lost 1.20 g.
546 words, about 3 min4pH partition hypothesis for aspirin and codeine
A medicinal chemist compares aspirin (acetylsalicylic acid, pKa 3.5) and codeine (a weak base, pKa of conjugate acid 8.2). A patient takes both drugs orally.
546 words, about 3 min5Temperature and vitamin C in orange juice by DCPIP titration
A student investigates the effect of temperature on the vitamin C content of orange juice. She measures 5.0 cm3 samples of fresh juice into test tubes, heats them in a water bath at 20, 40, 60 and 80 C for exactly 10 minutes, cools them rapidly, and titrates each with 0.0010 mol dm-3 DCPIP solution until the blue colour just disappears.
597 words, about 3 min