What is the standard enthalpy of formation of water vapor?

1 Answer
Jul 7, 2017

Answer:

Undoubtedly listed somewhere........

Explanation:

The #"standard molar enthalpy of formation"#, #DeltaH_"f"^@#, is the enthalpy associated with the formation of #1*mol# of substances from its constituent elements in their standard states under standard conditions...........

#H_2(g) + 1/2O_2(g) rarr H_2O(l) + DeltaH_f^@#.

I should make you dig for this, but in this scenario #DeltaH_f^@(H_2O)=-285.6*kJ*mol^-1#.........What does the negative value signify?