Question

Urgent!
Determinati caldura care se degaja la arderea unei cantitati de 1Kmol acetilena(C2H2) utilizand entalpiile molare de formare:
dHf°c2h2=+227kj/mol
dHf°h2o= -241,8kj/mol
dHf°co2= -393,5 kj/mol

Answer 1

n = 1kmol = 1000 moli C₂H₂

C₂H₂(g) + 5/2O₂(g) ⇒ 2CO₂(g) + H₂O(g) 

ΔH = 2ΔfH°CO₂(g) + ΔfH°H₂O(g) - [(ΔfH°C₂H₂+5/2ΔfH°O₂(g))] = 2*(-393,5) + (-241,8) - [(-227+0)] = -1255,8 KJ/mol

1 mol C₂H₂..............................1255,8 KJ
1000 moli................................Q  = 1255800 KJ = 1255,8 MJ