Which equation is balanced? CH4 + O2 ⟶ CO2 + H2O

Mg + 2HCl ⟶ MgCl2 + H2

Mg + P4 ⟶ Mg3P2

Using this reversible reaction, answer the questions below: n2o4 2no2 (colorless) (reddish-brown) -as the temperature increased, what happened to the n2o4 concentration? -was the formation of reactants or products favored by the addition of heat? -which reaction is exothermic? right to left or left to right? -if the change of enthalpy of this reaction when proceeding left to right is 14 kcal, which chemical equation is correct? n2o4 2no2 + 14 kcal n2o4 2no2, hr = +14 kcal n2o4 + 14 kcal 2no2 n2o4 2no2, hr = -14 kcal