Question

determina caldura exprimata in kj la ardera a 25 de moli de C7H16,daca se cunosc : MfC7H16=-188kj ,MjCO2=-393kj ,MjH2O=-242

Answer 1

C7H16(g) + 11O2(g) => 7CO2(g) + 8H2O(g) + Q

Mf=[(7MfCO2(g)+8MfH2O(g))]-[(MfC7H16(g)+11MfO2(g))] = [(7*(-393)+8*(-242)] - [(-188)+11*0] = -4687 + 188=-4499 Kj/mol

1 mol C7H16.............4499 Kj
25 moli.....................x=112475 Kj