Calculateur de Temps d'Électrolyse
Calculez le temps nécessaire pour une réaction d'électrolyse.
Rate Constant (k)
17.1982
Rate Constant (k) vs Pre-exponential Factor (A)
Formule
## Arrhenius Equation ### Formula **k = A × e^(−Ea / RT)** Where: - **k** = rate constant - **A** = pre-exponential (frequency) factor - **Ea** = activation energy (J/mol) - **R** = 8.314 J/(mol·K) - **T** = temperature (K) The rate constant increases exponentially with temperature and decreases with higher activation energy.
Exemple Résolu
A = 1 × 10¹⁰, Ea = 50,000 J/mol, T = 298 K.
- 01k = A × e^(-Ea/RT)
- 02k = 1×10¹⁰ × e^(-50000/(8.314×298))
- 03k = 1×10¹⁰ × e^(-20.18)
- 04k = 1×10¹⁰ × 1.71×10⁻⁹
- 05k = 17.1
Questions Fréquentes
What is the pre-exponential factor?
A (also called the frequency factor) relates to the frequency of molecular collisions and the probability that they have the correct orientation for reaction.
What units does k have?
The units depend on reaction order: zero order = M/s, first order = 1/s, second order = 1/(M·s).
How does doubling temperature affect k?
A rough rule is that k doubles for every 10 K increase near room temperature, but the actual effect depends on Ea.
Apprendre