What is the standard enthalpy of the reaction:

2 NO(g) + O2(g) → 2 NO2(g)?

Answerδh > 0explanationc₆h₆  (s)  → c₆h₆ (l)if you are changing it from a solid to a liquid, you are pretty much melting the solid. this requires heat energy. therefore, the reaction is endothermic (takes in energy); the system enthalpy increases as the reaction proceeds: δh > 0.

Zinc contains about 30 protons 

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