* HNO2 can show tautomerism and hybridisation remains the same.
(B) SOF2+2H2O→2HF+H2SO3
* Non - redox reaction, sulphurous acid undergoes tautomerism, hybridisation remains the same (sp3).
* HF can react with SiO2 (glass)
SiO2+4HF→SiF4+2H2O
(C) XeF4+H2O→Xe+O2+XeO3+HF
Redox reaction and HF can react with SiO2
(D) ClF6+3H2O→HClO+53+5HF
* Non - redox reaction
* HF reacts with glass and HClO3 can undergo tautomerism.