Q.

Identify disproportionation reaction

1 CH4+2O2→CO2+2H2O  
2 CH4+4Cl2→CCl4+4HCl  
3 2F2+2OH-→2F-+OF2+H2O  
4 2NO2+2OH-→NO2-+NO3-+H2O  

Ans.

(4)

2NO2+2OH-→NO2-+NO3-+H2O