All Flashcards
Define 'elementary reaction'.
A single-step reaction involving one or a few molecules.
What is an 'endothermic reaction'?
A reaction that absorbs energy from the surroundings; reactants + energy → products.
What is an 'exothermic reaction'?
A reaction that releases energy into the surroundings; reactants → products + energy.
Define 'activation energy (Ea)'.
The minimum energy required to start a reaction; the energy difference between reactants and the transition state.
What is the 'activated complex'?
The highest energy, most unstable point in a reaction; bonds are partially broken and formed.
Define the 'Arrhenius equation'.
The equation, , that describes how the rate constant of a reaction changes with temperature.
Differentiate between endothermic and exothermic reactions.
Endothermic: Absorbs energy, products have higher potential energy. Exothermic: Releases energy, products have lower potential energy.
Compare activation energy (Ea) and ΔH.
Ea: Energy to reach the transition state. ΔH: Overall energy change between reactants and products.
What's the difference between a first-order and second-order elementary reaction?
First-order: Rate depends on one reactant. Second-order: Rate depends on two reactants.
What is the effect of increasing temperature on reaction rate?
Generally, an increase in temperature increases the reaction rate.
What is the effect of a catalyst on activation energy?
A catalyst lowers the activation energy.
What is the effect of higher activation energy on reaction rate?
Higher activation energy leads to a slower reaction rate.