The ΔH f for CaO+2HCl ->3CO2+4H2O?

Answer 1

Favorite Answer

It would be a ΔH, not a ΔH f.

You'll need to look up the ΔH f for the four substances. Here is CaO:

http://webbook.nist.gov/cgi/cbook.cgi?Formula=CaO&...

The ΔH f is -635 kJ/mol for solid CaO

Here are some examples using Hess' Law and ΔH f values:

http://www.chemteam.info/Thermochem/HessLawIntro2....