Considering the following reactions, what type of reaction is represented by these two examples?

#Mg(s) + 1/2 O_2(g) -> MGO(s) + 146# kcal/mol
#H_2(g) + 1/2 O_2(g) -> H_2O(g)# #DeltaH = -57.82# kcal/mol.

1 Answer
Jul 7, 2016

Answer:

These are both #"enthalpies of formation"#, #DeltaH_f^@#

Explanation:

The #"enthalpy of formation"# is the enthalpy associated with the formation of one mole of product from its constituent elements under standard conditions.

Note that you have listed enthalpy as a product in the formation of #MgO#; of course you are aware that this represents a NEGATIVE #DeltaH_f^@#. If you ar not clear on why I should mention this, ask for clarification.