Given C(s) + O2(g) → CO2(g); ΔH = – 395 KJ
S(s) + O2(g) → SO2(g); ΔH = – 295 KJ
CS2(l) +3O2(g) → CO2(g) + 2SO2(g); ΔH = – 1110 KJ
The heat of foramation of CS2(l) is
.eq.(1) +2 eq.(2) - eq (3)
(eq. = equation)
C(s) + O2(g) → CO2(g); ΔH1 = – 395 KJ
2S(s) +2 O2(g) →2 SO2(g); ΔH2 =2( – 295) KJ
CO2(g) + 2SO2(g) →CS2(l) +3O2(g) ; ΔH3 = + 1110 KJ
C(s) + 2S(s) → CS2(l) ; ΔHf = ΔH1 + ΔH2 + ΔH3
ΔHf(CS2) = +125 KJ/mole