The mole

The balance reading is set by the model, to 0.01 g: a real spoonful varies. The balance was set to zero with the watch glass on its pan, so it reads below zero while the glass is off the pan.

The drops at the neck are drawn much larger than real drops, so each one moves the meniscus where you can see it. The magnified drop is a model: not to scale, and its colours are only labels. The waits are shortened.

A real drop of these solutions on a white tile is only a faint blue; the drops here are drawn bluer so flask A’s and flask B’s can be told apart.

With reduced motion, each step finishes at once.