Are group2 HYDROXIDES soluble or not ?

1 Answer
Mar 7, 2016

They are of low solubility in water.


It is generally not a good idea to regard compounds as being "soluble or not" - in practise, many compounds that are often regarded as "Insoluble in water" are actually soluble to a small extent. If you take magnesium hydroxide, for example, it is usually regarded as insoluble (it is used to form the suspension known as "milk of magnesia") but in fact it does dissolve in water at around 0.0007 g per 100 ml at 25 degrees C.

So the answer is that group 2 hydroxides are all very slightly soluble in water, but compared to group 1, their water solubility is MUCH lower. Magnesium hydroxide, 0.0007 g/100 ml at 25 degrees C - potassium hydroxide, 121 g/100ml at 25 degrees C.