Use Hess' law and the following thermochemical equations to...

Use Hess' law and the following thermochemical equations to produce the thermochemical equation for the reaction $\mathrm{C}(\mathrm{s},$ diamond) $\rightarrow \mathrm{C}(\mathrm{s},$ graphite).What is $\Delta H$ for the reaction? $$ \begin{array}{ll}{\text { a. } \mathrm{C}(\mathrm{s}, \text { graphite })+\mathrm{O}_{2}(\mathrm{g}) \rightarrow \mathrm{CO}_{2}(\mathrm{g})} & {\Delta H=-394 \mathrm{kJ}} \\ {\text { b. } \mathrm{C}(\mathrm{s}, \text { diamond })+\mathrm{O}_{2}(\mathrm{g}) \rightarrow \mathrm{CO}_{2}(\mathrm{g})} & {\Delta H=-396 \mathrm{kJ}}\end{array} $$

Use Hess' law and the following thermochemical
equations to produce the thermochemical equation for
the reaction $\mathrm{C}(\mathrm{s},$ diamond) $\rightarrow \mathrm{C}(\mathrm{s},$ graphite).What is
$\Delta H$ for the reaction?
$$
\begin{array}{ll}{\text { a. } \mathrm{C}(\mathrm{s}, \text { graphite })+\mathrm{O}_{2}(\mathrm{g}) \rightarrow \mathrm{CO}_{2}(\mathrm{g})} & {\Delta H=-394 \mathrm{kJ}} \\ {\text { b. } \mathrm{C}(\mathrm{s}, \text { diamond })+\mathrm{O}_{2}(\mathrm{g}) \rightarrow \mathrm{CO}_{2}(\mathrm{g})} & {\Delta H=-396 \mathrm{kJ}}\end{array}
$$

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Reaction Enthalpy

Reaction enthalpy is the heat change that occurs during a chemical reaction at constant pressure. It is a critical thermodynamic quantity representing the net energy absorbed or released in the process, and it can be determined directly or computed indirectly using methods such as Hess' Law.

Thermochemical Equations

Thermochemical equations are balanced chemical equations that include the enthalpy change associated with the reaction. They indicate not only the substances involved in the reaction but also whether energy is absorbed or released, which is essential for understanding and predicting reaction energetics.

Hess' Law

Hess' Law states that the total enthalpy change for a chemical reaction is independent of the pathway taken, provided the initial and final conditions are identical. This concept allows the calculation of reaction enthalpies by algebraically adding and subtracting the enthalpy changes of multiple steps or reactions, effectively using energy conservation principles.

Transcript

Please give Ace some feedback