CATIONSThis specific post is the one you want for the cation experiments we are doing in class at the moment:
One key point to note is about Barium, The Flow Chart we are using says that Barium ions do not precipitate out with Hydroxide ions. If the concentration of either is high enough, it does go milky/cloudy. Therefore, it can be confused for Magnesium. If you suspect an ion is Magnesium, test a new sample with sulfuric acid. If it precipitates out, it is really Barium. If nothing happens, it is Magnesium.
If you have any issues distinguishing between the colours of the precipitates, the following Flow Chart is sometimes easier to use. For example, it there is a coloured cation, it is tough to tell exactly what colour the precipitate is.