Reactants have a starting energy of 456.5KJ , and the products end with 254.8 KJ.

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

Consider the following reactions. (note: (s) = solid, (l) = liquid, and (g) = gas.) mg(s) + ½o2(g) → mgo(s) + 146 kcal/mole h2(g) + ½o2(g) → h2o(g), δh = -57.82 kcal/mole what type of reaction is represented by the previous two examples?

What is the percent by mass of oxygen in fe2o3