The Total solution for NCERT class 6-12
Calculate the standard enthalpy of formationof CH3OH(l) from the followingdata:
C(g) + O2(g) CO2(g) ; ΔcHθ = –393 kJ mol–1
The reaction that takes place during theformation of CH3OH(l) can be written as:
The reaction (1) can be obtained from the given reactions by following thealgebraic calculations as:
Equation (ii) + 2 ×equation (iii) – equation (i)
ΔfHθ [CH3OH(l)] = ΔcHθ + 2ΔfHθ [H2O(l)] – ΔrHθ
= (–393 kJ mol–1) + 2(–286 kJ mol–1) – (–726 kJ mol–1)