439 kJ/mol

Definition

439 kJ/mol is a measure of the standard enthalpy of formation, which represents the amount of energy released or absorbed when a substance is formed from its constituent elements under standard conditions. This value is particularly relevant in the context of understanding the structure and bonding of methane, as well as the concept of sp3 hybridization.

5 Must Know Facts For Your Next Test

1. The value of 439 kJ/mol represents the standard enthalpy of formation for methane (CH4), which is the simplest alkane and the primary component of natural gas.
2. This value indicates the amount of energy released when one mole of methane is formed from its constituent elements (carbon and hydrogen) under standard conditions.
3. The sp3 hybridization of the carbon atom in methane is directly related to the tetrahedral structure of the molecule, which is stabilized by the 439 kJ/mol of energy released during its formation.
4. The strong carbon-hydrogen bonds in methane, resulting from the sp3 hybridization, contribute to the stability and low reactivity of the molecule.
5. The high negative value of the standard enthalpy of formation for methane suggests that the formation of this compound from its elements is a highly exothermic process, releasing a significant amount of energy.

Review Questions

• Explain the relationship between the standard enthalpy of formation of 439 kJ/mol and the structure of methane.
  • The standard enthalpy of formation of 439 kJ/mol for methane (CH4) is directly related to the structure of the molecule, which is characterized by sp3 hybridization of the carbon atom. The sp3 hybridization results in a tetrahedral arrangement of the four bonds, with the carbon-hydrogen bonds being strong and stable. This stability is reflected in the large negative value of the standard enthalpy of formation, indicating that the formation of methane from its constituent elements is a highly exothermic process, releasing a significant amount of energy.
• Analyze how the standard enthalpy of formation of 439 kJ/mol for methane influences its reactivity and properties.
  • The high negative value of the standard enthalpy of formation for methane (439 kJ/mol) indicates that the formation of this compound from its elements is a highly exothermic process. This suggests that methane is a relatively stable and unreactive molecule, as the strong carbon-hydrogen bonds resulting from the sp3 hybridization require a significant amount of energy to break. The stability conferred by the 439 kJ/mol of energy released during the formation of methane contributes to its low reactivity and the ease with which it can be handled and stored, making it a valuable fuel source and a common component of natural gas.
• Evaluate the importance of understanding the standard enthalpy of formation of 439 kJ/mol for methane in the context of organic chemistry and the study of sp3 hybridization.
  • Understanding the standard enthalpy of formation of 439 kJ/mol for methane is crucial in the study of organic chemistry and the concept of sp3 hybridization. This value provides insight into the stability and reactivity of the methane molecule, which is the simplest alkane and a fundamental building block of organic compounds. The large negative value of the standard enthalpy of formation reflects the energy released during the formation of methane from its constituent elements, and this energy is directly related to the strong carbon-hydrogen bonds resulting from the sp3 hybridization of the carbon atom. Mastering the relationship between the standard enthalpy of formation, the molecular structure, and the properties of methane is essential for developing a comprehensive understanding of organic chemistry and the principles governing the behavior of simple hydrocarbon molecules.

Related terms

Enthalpy of Formation: The enthalpy change associated with the formation of a compound from its constituent elements in their standard states.

Standard Conditions: The reference state of 25°C (298.15 K) and 1 atm (101.325 kPa) pressure, used to define standard thermodynamic properties.

Hybridization:

The process of mixing atomic orbitals to form new hybrid orbitals, which are used to describe the bonding in molecules.