Consider the reaction ch3oh (l) →ch4 (g) + 1/2o2 (g). part a calculate δrh∘298.

To determine the standard heat of reaction, ΔHrxn°, let's apply the Hess' Law.

ΔHrxn° = ∑ (ν*ΔHf° of products) - ∑ (ν*ΔHf° of reactants)

where

ν si the stoichiometric coefficient of the substances in the reaction

ΔHf° is the standard heat of formation

The ΔHf° for the substances are the following:

CH₃OH (l) = - 238.4 kJ/mol

CH₄ (g) = - 74.7 kJ/mol

O₂ (g) = 0 kJ/mol

ΔHrxn° = (1 mol*-74.7 kJ/mol) - ∑ (1 mol*-238.4 kJ/mol)

ΔHrxn° = + 163.7 kJ