Question

b)
Calculate the standard enthalpy of formation of CH3OH(),
if the enthalpies of combustion of CH3OH(), carbon and
H, are -726kJ/mol, -393kJ/mol and -286kJ/mol
respectively.​

Answer 1

Answer:2C+O2+3H2 ---:2CH3OH

Standard enthalpy of formation must said for 1 Mole

Combustion value s of CH3OH is-726,,, Carbon is -393,, Hydrogen is-286

Explanation:for combustion and bond energy values we used formula

Enthalpy of reactant side minus enthalpy of product side

=(2×-726)-(2×-393+-3×-286=1644-1452=192

But standards enthalpy of formation must be done to 1 Mole so the answer is 192/2=86

I hope you understand well thank you