Compute the magnitude enthalpy of formation of liquid methyl alcohol in k J m o l − 1 , using the following data. Enthalpy of vaporization of liquid C H 3 O H = 38 k J / m o l . Enthalpy of formatio

Question

Compute the magnitude enthalpy of formation of liquid methyl alcohol in $k J m o l^{- 1}$ , using the following data. Enthalpy of vaporization of liquid $C H_{3} O H = 38 k J / m o l$ .

Enthalpy of formation of gaseous atoms from the elements in their standard states are:

H → $218 k J / m o l$ ; C → $715 k J / m o l$ ; O → $249 k J / m o l$ .

Bond Enthalpies:

C-H → $415 k J / m o l$ ; C-O → $356 k J / m o l$ ; O-H → $463 k J / m o l$ .

TestHub · Accepted Answer

Atoms formation: C = 715 4H = 4 × 218 = 872 O = 249 Total = 715 + 872 + 249 = 1836 Bond formation in CH₃OH(g): 3(C–H) = 3 × 415 = 1245 C–O = 356 O–H = 463 Total = 1245 + 356 + 463 = 2064 Δ H f ​ ( g ) = 1836 − 2064 = − 228 Liquid formation: Δ H f ​ ( l ) = − 228 − 38 = − 266

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