Why the oxides of nitrogen are purely acidic and that of arsenic and bismuth are basic
Group 15 elements are Nitrogen (N) (7), Phosphorus (P) (15), Arsenic (As) (33), Antimony (Sb) (51), Bismuth (Bi) (83).
Acidic character of oxides of group 15 elements decreases and basicity increases down the group. As we move down the group, the atomic size increases, electronegativity decreases, and metallic character increases. All these elements form two types of oxides: E2O3andE2O5 The oxide in the higher oxidation state of the element is more acidic than that of the lower oxidation state. Oxides of Nitrogen and phosphorous are acidic. As and Sb are amphoteric and Bismuth are basic.
On going down the atomic radius increases so ionisation energy decreases, this means that tendency of losing electrons increases which implies increase in metallic character ( as electron affinity also decreases ). We know that oxides and hydroxides of metals are basic in nature. Thus basic character increases down the group.
The basic nature can also be explained by the electro negativity concept and acid ionization constant (Ka). As the electro negativity of the orbital which contains the lone pair increases acidic strength increases.
Group 15 elements are Nitrogen (N) (7), Phosphorus (P) (15), Arsenic (As) (33), Antimony (Sb) (51), Bismuth (Bi) (83).
Acidic character of oxides of group 15 elements decreases and basicity increases down the group. As we move down the group, the atomic size increases, electronegativity decreases, and metallic character increases. All these elements form two types of oxides: E2O3andE2O5 The oxide in the higher oxidation state of the element is more acidic than that of the lower oxidation state. Oxides of Nitrogen and phosphorous are acidic. As and Sb are amphoteric and Bismuth are basic.
On going down the atomic radius increases so ionisation energy decreases, this means that tendency of losing electrons increases which implies increase in metallic character ( as electron affinity also decreases ). We know that oxides and hydroxides of metals are basic in nature. Thus basic character increases down the group.
The basic nature can also be explained by the electro negativity concept and acid ionization constant (Ka). As the electro negativity of the orbital which contains the lone pair increases acidic strength increases.
