<p>Hey I don't know if this is the exact wording of the question but...</p>
<p>When H2o melts / vaporizes is it exothermic or endo?
When H2o freezes / condenses is it exothermic or endo?</p>
<p>Also</p>
<p>For this reaction
H2o(L) --> H2o (G) does ^H = - ?</p>
<p>first is endothermic (it needs to get warmer to melt/vaporize)
second is exo (needs to get cooler to freeze or condense)</p>
<p>and yes, I'm pretty sure that is negative...it would say </p>
<p>heat + H2O(l) --> H2O(g)</p>
<p>Ok so also what bonds are broken when H2o (l) goes to h2o (g)? Is it covalent or hydrogen? Thanks.</p>
<p>Enthalpy is negative when a reaction is exothermic, no? So for that it should be positive.</p>
<p>hydrogen bonds are broken</p>
<p>And yeah, aniviel is right...wasn't thinking that through completely</p>
<p>It is simply the hydrogen bonds that hold the water molecules together that are broken, NOT the covalent bonds between the hydrogen and oxygen in a given water molecule. </p>
<p>Postive Enthalpy = Endothermic (Heat is on Reactant Side)
Negative Enthalpy = Exothermic (Heat is on the Product Side)</p>
<p>Can anyone provide a website to get all the Chemistry Formulas you need for the test?</p>