Question

the enthalpy change for the reaction H2O (l) = H2O (g) is called enthalpy of​

Answer 1

Answer:

Let's put it this way:

H2(g)+1/2O2(g)→H2O(g)

H2(g)+1/2O2(g)→H2O(l)

Although the reactants of the reactions are the same, pay attention to the products. H2O(g) and H2O(l) are different.

H2O(g)→H2O(l)

This reaction is exothermic, causing that H2O(l) is more stable than H2O(g). That is, std. enthalpy of formation for H2O(l)(-285.8kJ/mol) is smaller than that for H2O(g)(-241.82kJ/mol).

In a word, the different phase of substances do matter when talking about std. enthalpy of formation.

mark as brilliant answer ✌✌✌✌