Dau Corona !!!!!!!!!!!!
![Dau Corona class=](https://ro-static.z-dn.net/files/d9e/ae69b451cddf4eb95d4e6bd6414337fd.png)
stim ca
ΔHr° = ∑ΔH°f.produsi - ∑ΔH°f.reactanti
ΔHr° = [4ΔH°fHF + 2ΔH°fCF4] - [6ΔH°fF2 + ΔH°fC2H4]
ΔHr° = [4(-273) + 2(-680)] - [0 + 52]
ΔHr° = -2504 kJ