Activation energy (Ea) is the minimum amount of energy required for a chemical reaction to occur. It determines the rate at which reactants transform into products.
congrats on reading the definition of activation energy (Ea). now let's actually learn it.
Activation energy is often represented by the symbol $E_a$ and measured in joules (J) or kilojoules per mole (kJ/mol).
A higher activation energy means a slower reaction rate, while a lower activation energy indicates a faster reaction rate.
Catalysts lower the activation energy of a reaction without being consumed in the process.
The Arrhenius equation, $k = A e^{-E_a/RT}$, relates the rate constant $k$ to the activation energy $E_a$, where $R$ is the gas constant and $T$ is temperature in Kelvin.
Activation energy can be determined experimentally by measuring how reaction rates change with temperature.
Review Questions
What role does activation energy play in chemical reactions?
How does a catalyst affect activation energy?
Describe how you would determine activation energy using experimental data.
Related terms
Catalyst: A substance that increases the rate of a chemical reaction by lowering its activation energy without being consumed.
Arrhenius Equation: $k = A e^{-E_a/RT}$; an equation that shows how the rate constant ($k$) of a reaction depends on temperature ($T$) and activation energy ($E_a$).
Transition State: A high-energy state during a chemical reaction where old bonds are breaking and new bonds are forming.