What are the "true" values of units?The units that chemists use are international. A mole is the same worldwide. The SI unit of volume is a cubic metre although in practice a more useful unit is a cubic decimetre, dm3 which is called a litre in many countries. In the syllabus, and in examination questions, the IB uses dm3 and also cm3 but students who use litre, l, and millilitre, ml, respectively are not penalised...