A Calculadora Delta H ayuda a determinar el enthalpy change (ΔH) in a chemical reaction. Enthalpy change represents the heat absorbed or released during a reaction under constant pressure. This calculation is essential in thermodynamics, chemistry, and physics to predict reaction behavior, assess energy efficiency, and understand heat exchange in various systems.
Importance of Using a Delta H Calculator:
- Helps determine whether a reaction is endothermic (absorbing heat) or exothermic (releasing heat).
- Esencial para predicting reaction feasibility in industrial and laboratory settings.
- Utilizada en estudios de ingenieria y medio ambiente to assess heat transfer in processes.
- Ayuda en calculating energy efficiency in power plants, refrigeration, and combustion reactions.
Fórmula
The enthalpy change (ΔH) is calculated using the formula:
Delta H = (Sum of Enthalpy of Products) – (Sum of Enthalpy of Reactants)
For more detailed thermodynamic calculations:
- If heat (q) and work (w) are involved: Delta H = Change in Internal Energy + (Pressure × Change in Volume)
- For reactions occurring at constant pressure with heat transfer: Delta H = Heat Absorbed or Released at Constant Pressure
These formulas are widely used in termodinámica química to analyze heat exchange in various processes.
Delta H Reference Table
The table below provides general interpretations of enthalpy change values:
| Delta H (kJ/mol) | Tipo de reacción | Flujo de calor |
|---|---|---|
| ΔH > 0 | Endotérmica | Absorbe el calor |
| ΔH < 0 | Exotérmico | Releases heat |
| ΔH = 0 | Isotérmico | No net heat exchange |
This table helps chemists and engineers quickly understand reaction heat changes.
Example of Delta H Calculator
Scenario: Calculating Enthalpy Change for a Combustion Reaction
A combustion reaction of metano (CH₄) lanzamientos energía térmica when burning in oxygen:
CH₄ + 2O₂ → CO₂ + 2H₂O
Dado:
- Enthalpy of reactants: CH₄ = -74.8 kJ / mol, O₂ = 0 kJ / mol.
- Enthalpy of products: CO₂ = -393.5 kJ / mol, H₂O = -241.8 kJ / mol.
Usando la fórmula:
Delta H = [(1 × -393.5) + (2 × -241.8)] – [(1 × -74.8) + (2 × 0)]
Delta H = -876.3 + 74.8 = -801.5 kJ / mol
Interpretación:
The negative ΔH indicates that combustion of methane is an exothermic reaction, lo que significa que libera calor.
Preguntas frecuentes más comunes
A positive Delta H means the reaction is endotérmico, meaning it absorbs heat from the surroundings.
Delta H alone does not determine spontaneity; it must be analyze with entropy (ΔS) and Gibbs free energy (ΔG).
Sí un negative Delta H indica un Reacción exotérmica, where heat is release to the surroundings.