1.Calculate the enthalpy change (ΔHºrxn) for the following reaction: (The enthalpy of formation of aqueous sodium hydroxide is -469.60 kJ/mol. The enthalpy of formation of liquid water is -285.8 kJ/mol.)


2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g)

2.Do you know if the reaction is endothermic, thermodynamic, exothermic, or in its standard state?

3. The surroundings of the reaction will either
-get hotter,
-get cooler,
-neither get hotter nor get cooler due to the 2nd Law of Thermodynamics,
-get cooler if ΔG is negative; get hotter if ΔG is positive

1 answer

1. DHr = delta Hf
DHfrxn = (n*DHfproducts) - (n*DHfreactants)

From the number you obtain in the above you will have the information to answer 2 and 3.