ICO Part B (ORI) case studies
ICO Part B (ORI) · Put your knowledge to work in context.
The ICO Part B practical examination, often labelled ORI (Orientation), is the laboratory paper of the International Chemistry Olympiad. Each host country designs its own practical task, so the chemistry changes year to year, but the demands do not: you receive a bench, a set of reagents, an instruction sheet and a fixed amount of bench time, and you must produce both a clean experimental result and a written report that defends it. The ICO Part B (ORI) case studies are 5 cases and about 2,139 words.
1Cannula transfer of tert-butyllithium on a shared Schlenk line
On a shared Schlenk line, a student plans to transfer 40 mL of 2.5 M tert-butyllithium in pentane (100 mmol) into a 500 mL flask containing 0.90 g of a ketone in 30 mL THF at −78 °C under argon. The written plan says: attach the t-BuLi bottle to the manifold with a long needle, open the bottle to the vacuum line to draw the liquid into a graduated dropping funnel, then open the funnel to the flask.
441 words, about 2 min2Is the purple solid [Co(phen)2Cl2] or [Co(phen)3]Cl2?
CoCl2·6H2O (1.00 g, 4.20 mmol) and 1,10-phenanthroline (1.51 g, 8.40 mmol) are refluxed in methanol (40 mL) for 30 min. On cooling, a purple crystalline solid forms.
349 words, about 2 min3Assigning the aldol product from a crude mixture
A student condenses 4-methoxybenzaldehyde (1.36 g, 10.0 mmol) with acetone (2.90 g, 50.0 mmol) in ethanol using aqueous NaOH. After 2 h, the mixture is acidified, extracted with dichloromethane, and concentrated to a yellow oil (1.52 g).
493 words, about 2 min4Gravimetric sulfate: blank correction and a failed duplicate
A 0.5000 g sample of a soluble sulfate salt is dissolved in 150 mL of water and acidified with 2 mL of concentrated HCl. Sulfate is precipitated by adding 10% BaCl2 solution.
364 words, about 2 min5Temperature coefficient of a Zn/Cu cell
A student sets up the cell Zn(s) Zn(NO3)2(aq, 0.100 M) Cu(NO3)2(aq, 0.100 M) Cu(s) and measures the open-circuit potential with a high-impedance digital voltmeter at 298, 308, and 318 K. The cell is placed in a water bath, but readings are taken as soon as the thermometer shows the new temperature.
492 words, about 2 min