Question

Please show me how to do it I’m not understanding

Answer 1

To find the enthalpy of reaction of the given reaction, we have to use the following formula:

`\Delta Hr=\Sigma n\cdot\Delta Hf(p)-\Sigma n\cdot Hf(r)`

Where n is the coefficient of each substance, Hf(p) and Hf(r) are the enthalpies of formation of the products and the reactants respectively and Hr is the enthalpy of reaction.

The enthalpies of formation of each substance are:

`\begin{gathered} \Delta Hf_(H_2O)=-(285.8kJ)/(mol) \\ \Delta Hf_(SO_2)=-(296.9kJ)/(mol) \\ \Delta Hf_(H_2SO_4)=-(813.99kJ)/(mol) \end{gathered}`

The enthalpy of O2 is 0 since it is a pure compound.

Replace for the given values and find the enthalpy of reaction:

`\begin{gathered} \Delta Hr=2\cdot(-813.99)-(2\cdot(-296.9)+2\cdot(-285.8)) \\ \Delta Hr=-1627.98-(-1165.4) \\ \Delta Hr=-462.58 \end{gathered}`

It means that the enthalpy of reaction is -462.6 kJ.