Question

Using the standard enthalpies of formation, what is the standard enthalpy of reaction? CO(g)+H2​O(g)⟶CO2​( g)+H2​( g)

Answer 1

To calculate the standard enthalpy of reaction (∆H°) using standard enthalpies of formation (∆Hf°), you need to use the following equation:

∆H° = ∑∆Hf°(products) - ∑∆Hf°(reactants)

Let's find the standard enthalpies of formation for the given compounds first:

∆Hf°(CO) = -110.5 kJ/mol
∆Hf°(H2O) = -241.8 kJ/mol
∆Hf°(CO2) = -393.5 kJ/mol
∆Hf°(H2) = 0 kJ/mol

Now we can substitute these values into the equation to calculate the standard enthalpy of reaction:

∆H° = [∆Hf°(CO2) + ∆Hf°(H2)] - [∆Hf°(CO) + ∆Hf°(H2O)]
= [-393.5 kJ/mol + 0 kJ/mol] - [-110.5 kJ/mol - 241.8 kJ/mol]
= -393.5 kJ/mol + 352.3 kJ/mol
= -41.2 kJ/mol

Therefore, the standard enthalpy of reaction (∆H°) for the reaction CO(g) + H2O(g) ⟶ CO2(g) + H2(g) is -41.2 kJ/mol