Chemistry Help: Reactions for the Standard heat of formation?

Write the reactions for the Standard heat of formation of these from their elements in the standard state:





a)HNO3(l)


b) Ca(NO3)2(l)


c) NaOH (s)


d) H2O(l)








Can anyone please verify the following answers...





a) 1/2 H2(g) + 1/2 N2(g) + 3/2 O2(g) -----%26gt; HNO3(l)





b) Ca(s) + N2(g) + 3O2(g) -----%26gt; Ca(NO3)2(l)





c) Na(s) + 1/2 O2(g) + 1/2 H2(g) -----%26gt; NaOH(s)





d) H2(g) + 1/2 Os(g) -----%26gt; H2O(l)

Chemistry Help: Reactions for the Standard heat of formation?
Yep - you got 'em. Just remember you always form only 1 mole of the compound.
Reply:The reactions given here by you are very correct. As the std. heat of formation of a compound is the the heat liberated at the time of formation of per mole of the compound from it's constituent elements in their std. state at std. temperature.





It was a nice pleasure to help you.