Give reasons:
(i) Alkaline earth metal hydroxides are less basic than alkali metal hydroxides.
(ii) Alkali & alkaline earth metal hydrides are ionic in nature.
(iii) Group 1 elements are called alkali metals.
(iv) Be resembles Al.
(v) The fluorides of alkaline earth & alkali metal are relatively less soluble than chlorides.
Answers
i) The alkali earth metal hydroxides are less soluble in water compared to the alkali metal hydroxides. Due to the higher enthalpies, smaller ionic size and greater lattice energy the alkaline earth metal hydroxides are less basic than alkali metal hydroxides
ii) Alkali & alkaline earth metal hydrides are ionic in nature because these compounds most actively form bond with hydrogen to form metal hydrides. These metal hydrides are also known as saline hydrides or pseudo-halides
iii) When the group I elements react with water they form strong alkalis. Hence the six elements are grouped.
iv) Due to the similarity in size of their ions, charge and radius ratio beryllium and aluminum show similar properties and they exhibit diagonal relationship.
v) The chlorides, iodides and bromides of alkaline earth metals are ionic in nature and hence they are soluble in water. Due to high lattice energy and low anion size of fluorides, it is relatively less soluble compared to other halides.