I think you add 29.57 + 80 and the answer would be 30.37
NO₂ is a brown gas while N₂O₄ is colorless. If heating causes a brown color to persist, then this means that heating causes the reaction to shift backwards and produce NO₂. Therefore, the reaction must be exothermic.
The information that the coefficients of a balanced equation give about the reactants are to tell how many moles of reactants are needed and how many moles of product can be produced.
Its b Fe(s) <span> Fe</span>2+(aq) + 2e– <span><span> </span>E</span><span> = </span><span>+0.44 V</span>
