CONCEPT:

Nature of Oxides:

• Metallic oxides → generally basic
• Non-metal oxides → generally acidic
• Borderline/metalloids → often amphoteric
• Lower oxidation state → more basic
• Higher oxidation state → more acidic

Lewis Acid:

• Species that accepts an electron pair

Electron Deficient Molecules:

• Have incomplete octet
• Act as Lewis acids

EXPLANATION:

Statement I:

We check each pair:

1. [SiO₂, CO₂]
   • Both are non-metal oxides
   • Both are acidic
     → Not amphoteric

1. [SnO, SnO₂]
   • Sn is a metal with variable oxidation states
   • Both oxides show amphoteric behavior

1. [PbO, PbO₂]
   • Pb behaves similarly to Sn
   • Both oxides are amphoteric

1. [GeO, GeO₂]
   • Ge is metalloid
   • GeO → more basic
   • GeO₂ → more acidic
     → Not both amphoteric

Conclusion (Statement I):

Only 2 pairs are amphoteric:

• SnO / SnO₂
• PbO / PbO₂

Statement I is true

Statement II:

BF₃:

• Boron has only 6 electrons around it → electron deficient
• Hence, it can accept a lone pair → acts as Lewis acid

• Reacts with NH₃:

  BF₃ + NH₃ → F₃B ← NH₃ (adduct formation)

• Hybridization of B = sp²
• Geometry = trigonal planar

Conclusion (Statement II):

All statements are correct

Statement II is true

FINAL ANSWER:

Both Statement I and Statement II are true