Question

Calculate the change in enthalpy (LaTeX: \DeltaΔH) of a reaction with the following information:

Energy of Reactants = 129 kJ

Energy of the Products = 110 kJ

Energy of the Transition State = 198 kJ

Answer 1

Answer: -19 kJ

Step-by-step explanation:

The change in enthalpy
`\Delta H` is mathematically expressed as the difference between the the total potential energy of products
`U_(products)` and the potential energy of the reactants
`U_(reactants)`:

`\Delta H=U_(products)-U_(reactants)`

Where:

`U_(products)=110 kJ=110 (10)^(3)J`

`U_(reactants)=129 kJ=129 (10)^(3)J`

Then:

`\Delta H=110 kJ-129 kJ`

`\Delta H=-19 kJ` The negative sign in this result means we have a negative enthalpy, hence an exothermic reaction (where heat is released).