Answer: -19 kJ
Explanation:
The change in enthalpy [tex]\Delta H[/tex] is mathematically expressed as the difference between the the total potential energy of products [tex]U_{products}[/tex] and the potential energy of the reactants [tex]U_{reactants}[/tex]:
[tex]\Delta H=U_{products}-U_{reactants}[/tex]
Where:
[tex]U_{products}=110 kJ=110 (10)^{3}J[/tex]
[tex]U_{reactants}=129 kJ=129 (10)^{3}J[/tex]
Then:
[tex]\Delta H=110 kJ-129 kJ[/tex]
[tex]\Delta H=-19 kJ[/tex] The negative sign in this result means we have a negative enthalpy, hence an exothermic reaction (where heat is released).
