Use bond energies to calculate the approximate enthalpy change for the following reactions. State whether the reaction in exothermic or endothermic.
a) 2H2 + O2 - 2H2O

Question

Use bond energies to calculate the approximate enthalpy change for the following reactions. State whether the reaction in exothermic or endothermic. 
a) 2H2 + O2 -> 2H2O

anonymous · Answer

Are you given any bond enthalpies to answer this question?

anonymous · Answer

Use this equation. The bond energies should be in the back of your book or in a reference packet for Thermodynamics. Also, don't forget to multiply the numbers you are given by the corresponding coefficients from the chemical reaction.
$$\Delta H= \Delta H (products) - \Delta H (reactants)$$