2H2+ O2 —> 2H2 O
What mass of oxygen gas (in grams) is needed to completely react with 100.0 grams of hydrogen gas to form water
___ g O2

Which best describes the activation energy of a chemical reaction? a. the combined energy of all the reactants b. the amount of energy required for a reaction to occur c. the difference in energy between products and reactants d. the potential energy stored in the bonds of reactants and products