Identify disproportionation reaction CH4 + O2 → CO2 + H2OCH4 + Cl2 → CCl4 + HClF2 + OH– → F– + OF2 +H2ONO2 + OH– → NO2– + NO3– + H2O

A disproportionation reaction is a redox reaction in which a single element is both oxidized and reduced. It occurs when an element in an intermediate oxidation state is converted to two different oxidation states, one higher and one lower than the original state.

1. CH4 + O2 → CO2 + H2O: This is a combustion reaction, not a disproportionation reaction. Carbon is oxidized from -4 in CH4 to +4 in CO2, but there is no reduction of carbon.

2. CH4 + Cl2 → CCl4 + HCl: This is also not a disproportionation reaction. Carbon is oxidized from -4 in CH4 to +4 in CCl4, and Chlorine is reduced from 0 in Cl2 to -1 in HCl.

3. F2 + OH– → F– + OF2 + H2O: This is a disproportionation reaction. Fluorine is reduced from 0 in F2 to -1 in F– and is oxidized from 0 in F2 to +2 in OF2.

4. NO2 + OH– → NO2– + NO3– + H2O: This is also a disproportionation reaction. Nitrogen is reduced from +4 in NO2 to +3 in NO2– and is oxidized from +4 in NO2 to +5 in NO3–.