The standard enthalpies of formation for several substances are given below: Determine the DH° for the reaction below.

Question

The standard enthalpies of formation for several substances are given below:  Determine the DH° for the reaction below.

Quizplus · Accepted Answer

To calculate the enthalpy change for the given reaction, we need to use the enthalpies of formation of the reactants and products. 
Reactant:
2CO(g) has a standard enthalpy of formation of -566.0 kJ/mol
Product: 
CO2(g) has a standard enthalpy of formation of -393.5 kJ/mol
H2O(l) has a standard enthalpy of formation of -285.8 kJ/mol
Therefore,
ΔH° = (∑nΔH°products) - (∑nΔH°reactants)
= (1 × -393.5 kJ/mol + 2 × -285.8 kJ/mol) - (2 × -566.0 kJ/mol)
= -2219.9 kJ/mol
Therefore, the correct answer is B.

The Standard Enthalpies of Formation for Several Substances Are Given