Question

Least basic oxide among the following is
Beo
Mgo
Cao
Sro​

Answer 1

Answer:

mgo is the correct answer

Answer 2

We have to find out least basic among the following

1. BeO
2. MgO
3. CaO
4. SrO

solution : we should Fazan's rule,

when size of cation increases, polarising power decreases so covalent character decreases it means ionic character increases. and hence basic character increases down the group for metallic oxide.

here metals Be, Mg , Ca and Sr come from the same group (alkaline earth metals) and we know down the group, size of metals increases. so basic strength increases down the group.

therefore Order of basic strength will be

BeO < MgO < CaO < SrO

Therefore BeO is least basic oxide.