Question

For Enthalpy? the formula and what answer you all got? The sum(product)-The sum(reactant)

Answer 1

`CH_3OH to 2H_2+CO`

Methanol,

decomposes into hydrogen (`H-H`) and carbon monoxide (`C-=O`) gases, here.

We're breaking three `C-H` bonds, one `C-O` bond, one `O-H` bond, and forming two `H-H` bonds, and one `C-=O` bond.

Forming bonds is exothermic, and breaking bonds is endothermic, so with using your data,

`DeltaH = SigmaDeltaH_b - SigmaDeltaH_f`

where b and f indicate bonds broken and bonds formed, respectively. Hence

`DeltaH = (3mol * (413kJ)/(mol) + 1mol * (358kJ)/(mol) + 1mol * (436kJ)/(mol)) - (1mol * (1072kJ)/(mol) + 2mol * (432kJ)/(mol)) approx 97kJ`

is the enthalpy of this reaction, which is energetically unfavorable.