Analyze Periodic Trends: Metallic oxides are generally basic, while non-metallic oxides are acidic. Within a group, basic character increases down the group as metallic character increases. Across a period, acidic character increases.
Analyze Al2O3 (Aluminium Oxide): Aluminium is amphoteric. Al2O3 reacts with both acids and bases [Class 12 Chemistry, Unit 4, Sec 4.4]. It is amphoteric.
Analyze Sb2O3 (Antimony(III) Oxide): Antimony is a metalloid (Group 15). Its oxide is amphoteric.
Analyze SeO2 (Selenium Dioxide): Selenium is a non-metal (Group 16). Non-metallic oxides are acidic. SeO2 is acidic.
Analyze Bi2O3 (Bismuth(III) Oxide): Bismuth is a metal (Group 15, below Antimony). As we move down Group 15, the metallic character increases (N<P<As<Sb<Bi). Consequently, the basic nature of their oxides increases. Bi2O3 is purely basic.
Conclusion: Among the given options, Bi2O3 is the only purely basic oxide.
Practice Mode Available
Master this Topic on Sushrut
Join thousands of students and practice with AI-generated mock tests.