Question

why be and mg undergoes hydrolysis while ca sr ba undeeoes dehydration?
may be due to covalent nature of be and mg?​

Answer 1

$\fbox\pink{A}\fbox\blue{n}\fbox\purple{s}\fbox\green{w}\fbox\red{e}\fbox\orange{r}$The hydrated chloride, bromides and iodides of Ca, Sr and Ba can be dehydrated on heating but those of Be and Mg cannot be dehydrated as they undergo hydrolysis to form corresponding hydroxides.

So, Magnesium chloride forms Magnesium hydroxide and so on.