Finding the missing mass

Chemists often say that chemistry is like cooking, but chemistry seems to have the more interesting pitfalls. Imagine baking a cake – mixing the butter and sugar, adding in the eggs, sifting in the flour, baking powder and the milk, pouring the batter and putting it in the oven. Soon, the smell of a risen cake permeates the house and you open the oven door, and what happened? In place of a large beautiful cake, there is barely enough for a couple of bites.

Luckily for home cooks, this just isn’t the way that cooking fails. Food is too raw, or meat is burnt, or maybe someone adds too much salt – but the food is always there. Laboratory chemistry is one of those places where that’s not always the case. You can open the laboratory vacuum oven, or look in at the Buchner funnel, or worse yet, watch your expected kilograms of material gather in the centrifuge basket, and you realise: there’s not very much compound, many kilograms less than is expected.