All Flashcards
What are the key differences between exothermic and endothermic reactions?
Exothermic: Releases heat, ΔH < 0, products have lower energy. Endothermic: Absorbs heat, ΔH > 0, products have higher energy.
How do energy diagrams differ for exothermic vs. endothermic reactions?
Exothermic: Downward slope from reactants to products. Endothermic: Upward slope from reactants to products.
In a typical energy diagram, what does the y-axis represent?
Potential Energy (usually in kJ or J).
In a typical energy diagram, what does the x-axis represent?
Reaction Progress or Reaction Coordinate.
What is Activation Energy (Ea)?
The minimum energy required to start a chemical reaction.
Define Enthalpy (ΔH).
A measure of the heat energy exchanged in a reaction at constant pressure; ΔH = H(products) - H(reactants).
What is an exothermic reaction?
A reaction that releases energy, resulting in products having lower energy than reactants (ΔH < 0).
What is an endothermic reaction?
A reaction that absorbs energy, resulting in products having higher energy than reactants (ΔH > 0).
Define the term 'activated complex'.
An unstable intermediate state at the peak of the energy diagram.
What is latent heat?
The heat absorbed or released during a phase change at constant temperature.