Why Some Compounds Don't Exist
A comprehensive guide for JEE Mains & Advanced. Understand the limits of chemical bonding: Sterics, Orbitals, and Redox.
Core Concepts
The 4 Laws of Non-Existence
Before memorizing lists, master the reasons. 90% of non-existent compound questions in JEE rely on these four principles. Click a card to explore.
Absence of d-orbitals
Period 2 elements (N, O, F) cannot expand octet.
Steric Hindrance
Central atom too small to hold many large groups.
Inert Pair Effect
Heavier elements (Pb, Bi, Tl) prefer lower oxidation states.
Redox Incompatibility
Reducing anion destroys oxidizing cation.
Select a concept above
Click on one of the four cards to see detailed explanations and specific examples relevant to JEE questions.
Case Studies
The Graveyard of Compounds
Explore the specific compounds often asked in exams. Click on a formula to perform an "Autopsy" and see why it fails.
Select a compound from the list to view its analysis.
Visualizing the Trends
Understanding the underlying data helps predict the existence of unknown compounds.
Inert Pair Effect: Group 14 Stability
Notice how the stability of the +4 oxidation state plummets for Lead (Pb), making PbI4 unstable.
Steric Crowding: Si vs C
Why SiCl62- is unstable while SiF62- exists. Chlorine atoms are simply too large.