In which reaction does the oxidation number of oxygen increase? in which reaction does the oxidation number of oxygen increase? 2so2 (g) + o2 (g) → 2so3 (g) mgo (s) + h2o (l) → mg(oh)2 (s) 2h2o (l) → 2h2 (g) + o2 (g) ba(no3)2 (aq) + k2so4 (aq) → baso4 (s) + 2kno3 (aq) hcl (aq) + naoh (aq) → nacl (aq) + h2o (l)?

The answer is :

2H₂O (l) >2H₂ (g) + O₂ (g)  

That is ,

Oxidation number of oxygen increases in reaction :

2H₂O (l) >2H₂ (g) + O₂ (g)  

In H₂O, oxidation number of oxygen is -2 but in O₂ molecule it is 0.

So, oxidation number of oxygen increases in this reaction that is from -2 to 0.

So in the reaction that is 2H₂O (l) >2H₂ (g) + O₂ (g) ,  oxidation number of oxygen increases .