The standard enthalpy of formation of solid copper oxide (CuO) is -299 kJ/mol.
The enthalpy of formation (ΔHf°) is a specific type of enthalpy change that occurs when one mole of a compound is formed from its constituent elements in their standard states under standard conditions (typically 25 °C and 1 atm pressure). For copper oxide (CuO), this value indicates the energy released or absorbed during its creation from elemental copper (Cu) and oxygen gas (O₂).
Understanding the Standard Enthalpy of Formation of CuO
The standard enthalpy of formation for copper oxide (CuO) is a critical thermodynamic property used in chemistry to calculate enthalpy changes for various reactions involving CuO.
- Definition: The value of -299 kJ/mol signifies that when one mole of solid copper oxide is formed directly from solid copper and gaseous oxygen in their standard states, 299 kilojoules of energy are released.
- Exothermic Reaction: A negative enthalpy change (ΔH < 0) indicates an exothermic process, meaning that heat is released to the surroundings during the formation of copper oxide. This suggests that CuO is more stable than its constituent elements in their standard states.
Key Data for Copper Oxide (CuO)
| Property | Value | Unit |
|---|---|---|
| Standard Enthalpy of Formation | -299 | kJ/mol |
| Chemical Formula | CuO | |
| State (at standard conditions) | Solid | |
| Nature of Formation Reaction | Exothermic |
Importance of Enthalpy of Formation
Understanding the standard enthalpy of formation of compounds like copper oxide is crucial for several reasons in chemistry and material science:
- Predicting Reaction Feasibility: It helps in predicting whether a chemical reaction will be spontaneous or non-spontaneous under given conditions.
- Calculating Reaction Enthalpies: Using Hess's Law, the enthalpy of formation values for reactants and products can be used to calculate the overall enthalpy change (ΔHrxn) for any chemical reaction, providing insight into its energy requirements or output.
- Thermodynamic Stability: A more negative enthalpy of formation generally indicates a more thermodynamically stable compound relative to its elements.
- Industrial Applications: These values are essential in designing and optimizing industrial processes, such as those involving the production of metal oxides or catalysts, by evaluating their energy efficiency.
What is Copper Oxide?
Copper oxide refers to several compounds of copper and oxygen. The most common forms are:
- Copper(II) Oxide (CuO): Also known as cupric oxide, it is a black solid. It is widely used as a pigment in ceramics, a catalyst in various chemical reactions, and in batteries.
- Copper(I) Oxide (Cu₂O): Also known as cuprous oxide, it is a red or reddish-brown solid. It is used as a fungicide and a pigment.
When discussing "enthalpy of copper oxide" without further specification, it often refers to the more common copper(II) oxide (CuO), which is what the provided enthalpy value corresponds to.
For further exploration of enthalpy and chemical thermodynamics, you can refer to resources on chemical reactions and energy or thermochemistry.
