Memorising Solubility Rules (1 Viewer)

[gamja]

I made notes on solubility rules and memorised all but the 'mostly soluble' compounds. Any tips on the best way to memorise these? Mnemonics are good, but are there ones which cover all the ones here?



[i.e. I learnt also that HydroxideCarbonatePhosphates are mostly Insoluble - a rule not covered in many mnemonics.]

 

[wizzkids]

To be honest, I'm not sure why so many students try to memorise the solubility rules (and let's face it, they aren't consistent, because there are so many exceptions). The data is given to you in the examination, in the form of the Table of Solubility Constants. Sure, it is useful to be able to generalise that cations like sodium and potassium compounds are always soluble, and anions like chloride and nitrate are almost always soluble, but beyond that, you need to refer to the Table of Solubility Constants. In reality, there are no hard and fast rules, and to believe so ignores the deeper reality of dynamic equilibrium. It can also lead to misconceptions about the sparingly soluble compounds like calcium hydroxide.
I would be interested to hear comments about this from experienced Chemistry tutors and teachers.