Question

Calculate the enthalpy of reaction for 2CO + O2 → 2CO2. given the following bond energies:

Answer 1

Answer : The enthalpy change for the reaction is 1043 kJ/mol.

Explanation :

The given chemical reaction is:

$2CO+O_2\rightarrow 2CO_2$

As we know that:

The enthalpy change of reaction = E(bonds broken) - E(bonds formed)

$\Delta H=[(2\times B.E_{C\equiv O})+(1\times B.E_{O\equiv O})]-[2\times B.E_{C=O}]$

Given:

$B.E_{C\equiv O}$ = 1074 kJ/mol

$B.E_{O\equiv O}$ = 499 kJ/mol

$B.E_{C=O}$ = 802 kJ/mol

Now put all the given values in the above expression, we get:

$\Delta H=[(2\times 1074kJ/mol)+(1\times 499kJ/mol)]-[2\times 802kJ/mol]$

$\Delta H=1043kJ/mol$

Therefore, the enthalpy change for the reaction is 1043 kJ/mol.