target Reaction:Â Â 2C(s) + H2(g) --------------->
C2H2(g)
Given reactions are arranged to get the target reaction, by
stiochiometric coefficient selection
-1x {C2H2(g) + 5/2 O2(g)---->2CO2(g) + H2O(l) } Â Â
ΔH1=  -1300.kJ
2x {C(s) + O2(g)----->CO2(g) Â Â Â }
                      Â
ΔH2= -394kJ
1x{ H2(g) + O2(g) -------> H2O(l)
}Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
ΔH3= -286kJ
Same alegrabaic operation is to be carried out on enthapy
change
So ΔH target = -1(ΔH1=  -1300.kJ) + 2x(ΔH2= -394kJ) +
(ΔH3= -286kJ)
                   Â
= 1300 +(- 788) + (-286) = 226 KJ
